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Sample records for caii triplet spectroscopy

  1. Automatic stellar spectra parameterisation in the IR CaII triplet region

    CERN Document Server

    Kordopatis, G; de Laverny, P; Bijaoui, A; Hill, V; Gilmore, G; Wyse, R F G; Ordenovic, C

    2011-01-01

    (Abridged) Galactic archaeology aims to determine the evolution of the Galaxy from the chemical and kinematical properties of its stars. The analysis of current large spectroscopic surveys (thousands of stars) and future ones (millions of stars) require automated analysis techniques to obtain robust estimates of the stellar parameters. Several on-going and planned spectroscopic surveys have selected their wavelength region to contain the IR CaII triplet and this paper focuses on the automatic analysis of such spectra. We investigated two algorithms, MATISSE and DEGAS, both of which compare the observed spectrum to a grid of synthetic spectra, but each uses a different mathematical approach for finding the optimum match and hence the best stellar parameters. We identified degeneracies in different regions of the HR diagram: hot dwarfs and giants share the same spectral signatures. Furthermore, the surface gravity of cooler dwarfs is difficult to determine accurately. These effects are intensified when the info...

  2. A STIS Atlas of CaII Triplet Absorption Line Kinematics in Galactic Nuclei

    CERN Document Server

    Batcheldor, D; Valluri, M; Mandalou, J; Merritt, D

    2013-01-01

    The relations observed between supermassive black holes and their host galaxies suggest a fundamental link in the processes that cause these two objects to evolve. A more comprehensive understanding of these relations could be gained by increasing the number of supermassive black hole mass (M) measurements. This can be achieved, in part, by continuing to model the stellar dynamics at the centers of galactic bulges using data of the highest possible spatial resolution. Consequently, we present here an atlas of galaxies in the Space Telescope Imaging Spectrograph (STIS) data archive that may have spectra suitable for new M estimates. Archived STIS G750M data for all non-barred galactic bulges are co-aligned and combined, where appropriate, and the radial signal-to-noise ratios calculated. The line-of-sight velocity distributions from the CaII triplet are then determined using a maximum penalized likelihood method. We find 19 out of 42 galaxies may provide useful new M estimates since they are found to have data...

  3. Study of the Sextans dwarf spheroidal galaxy from the DART CaII triplet survey

    CERN Document Server

    Battaglia, G; Helmi, A; Irwin, M; Parisi, P; Hill, V; Jablonka, P

    2010-01-01

    We use VLT/FLAMES intermediate resolution (R~6500) spectra of individual red giant branch stars in the near-infrared CaII triplet (CaT) region to investigate the wide-area metallicity properties and internal kinematics of the Sextans dwarf spheroidal galaxy (dSph). Our final sample consists of 174 probable members of Sextans with accurate line-of-sight velocities (+- 2 km/s) and CaT [Fe/H] measurements (+- 0.2 dex). We use the MgI line at 8806.8 \\AA\\, as an empirical discriminator for distinguishing between probable members of the dSph (giant stars) and probable Galactic contaminants (dwarf stars). Sextans shows a similar chemo-dynamical behaviour to other Milky Way dSphs, with its central regions being more metal rich than the outer parts and with the more metal-rich stars displaying colder kinematics than the more metal-poor stars. Hints of a velocity gradient are found along the projected major axis and along an axis at P.A.=191 deg, however a larger and more spatially extended sample may be necessary to p...

  4. Triplet State Resonance Raman Spectroscopy

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N. H.; Pagsberg, Palle Bjørn;

    1978-01-01

    Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied......Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied...

  5. Triplet absorption spectroscopy and electromagnetically induced transparency

    Science.gov (United States)

    Ghafoor, F.; Nazmitdinov, R. G.

    2016-09-01

    Coherence phenomena in a four-level atomic system, cyclically driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical Stark effect. Two dark lines with a Fano-like profile arise in the triplet absorption spectrum with anomalous dispersions. We provide conditions to control the widths of the transparency windows by means of the relative phase of the driving fields and the intensity of the microwave field, which closes the optical system loop. The effect of Doppler broadening on the results of the triplet absorption spectroscopy is analysed in detail.

  6. A new synthetic library of the Near-Infrared CaII triplet indices. I.Index Definition, Calibration and Relations with stellar atmospheric parameters

    CERN Document Server

    Du, Wei; Zhao, Yong-Heng

    2011-01-01

    Adopting the SPECTRUM package, we have synthesized a set of 2,890 Near-InfraRed (NIR) synthetic spectra with a resolution and wavelength sampling similar to the SDSS and the forthcoming LAMOST spectra. During the synthesis, we have applied the `New grids of ATLAS9 Model Atmosphere' to provide a grid of local thermodynamic equilibrium (LTE) model atmospheres. This synthetic stellar library is composed of 1,350 solor scaled abundance (SSA) and 1,530 non-solar scaled abundance (NSSA) spectra, grounding on which we have defined a new set of NIR CaII triplet indices and an index CaT as the sum of the three. Then, these defined indices have been automatically measured on the synthetic spectra and calibrated with the indices computed on the observational spectra from the INDO-U.S. stellar library. In order to check the effect of alpha-element enhancement on the so-defined CaII indices, we have compared indices measured on the SSA spectra with those on the NSSA ones at the same terns of stellar parameters (Teff, log ...

  7. Temporal Evolution of the Scattering Polarization of the CaII IR Triplet in Hydrodynamical Models of the Solar Chromosphere

    CERN Document Server

    Carlin, E S; Bueno, J Trujillo

    2012-01-01

    Velocity gradients in a stellar atmospheric plasma have an impact on the anisotropy of the radiation field that illuminates each point within the medium, and this may in principle influence the scattering line polarization that results from the induced atomic level polarization. Here we analyze the emergent linear polarization profiles of the Ca II infrared triplet after solving the radiative transfer problem of scattering polarization in time-dependent hydrodynamical models of the solar chromosphere, taking into account the impact of the plasma macroscopic velocity on the atomic level polarization. We discuss the influence that the velocity and temperature shocks in the considered chromospheric models have on the temporal evolution of the scattering polarization signals of the Ca II infrared lines, as well as on the temporally averaged profiles. Our results indicate that the increase of the linear polarization amplitudes caused by macroscopic velocity gradients may be significant in realistic situations. We ...

  8. Precision spectroscopy with ultracold {sup 87}Rb{sub 2} triplet molecules

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Christoph

    2011-10-19

    In this thesis I report precision spectroscopy with ultracold {sup 87}Rb{sub 2} triplet molecules where we use lasers to couple the states in different molecular potentials. We study in detail states of the a {sup 3} sum {sup +}{sub u} and (1) {sup 3} sum {sup +}{sub g} potentials. These states are of great importance for transferring weakly bound molecules to the ro-vibrational triplet ground state via states of the excited potential. As most experiments start from molecules in their X {sup 1} sum {sup +}{sub g} ground state, the triplet states were hard to access via dipole transitions and remained largely unexplored. The measurements presented in this thesis are the first detailed study of diatomic {sup 87}Rb{sub 2} molecules in these states. Our experiments start with an ultracold cloud of {sup 87}Rb atoms. We then load this cloud into an optical lattice where we use a magnetic Feshbach resonance at 1007.4 G to perform a Feshbach association. After we have removed all unbound atoms, we end up with a pure sample of weakly bound Feshbach molecules inside the optical lattice. The optical lattice prevents these molecules from colliding with each other which results in molecular lifetimes on the order of a few hundred milliseconds. In the first set of experiments, we use a laser coupling the Feshbach state to the excited (1) {sup 3} sum {sup +}{sub g} triplet state to map out its low-lying vibrational (v = 0.. 15), rotational, hyperfine, and Zeeman structure. The experimental results are in good agreement with calculations done by Marius Lysebo and Prof. Leif Veseth. We then map out in detail the vibrational, rotational, hyperfine, and Zeeman structure of the a {sup 3} sum {sup +}{sub u} triplet ground state using dark state spectroscopy with levels in the (1) {sup 3} sum {sup +}{sub g} potential as an intermediate state. In this scheme we are able to access molecules in triplet states because our Feshbach state has strong triplet character. Interestingly, it

  9. Ca II triplet spectroscopy of RGB stars in NGC 6822: kinematics and metallicities

    CERN Document Server

    Swan, Jesse; Tolstoy, Eline; Irwin, Mike J

    2016-01-01

    We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at 8500 Angstroms was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line of sight extinction was individually estimated for each target star to accommodate the variable reddening across NGC 6822. The mean radial velocity was found to be v_helio = (52.8 +/- 2.2) km/s with dispersion rms = 24.1 km/s, in agreement with other studies. Ca II triplet equivalent widths were converted into [Fe/H] metallicities using a V magnitude proxy for surface gravity. The average metallicity was [Fe/H] = (-0.84 +/- 0.04) with dispersion rms = 0.31 dex and interquartile range 0.48. Our assignment of individual reddening values makes our analysis more sensitive to spatial variations in metallicity than previous studies. We divide our sample into metal-rich and metal-poor stars; the former are found to cluster towards small radii with the metal-poor stars more evenly distribut...

  10. Ca II triplet spectroscopy of RGB stars in NGC 6822: kinematics and metallicities

    Science.gov (United States)

    Swan, J.; Cole, A. A.; Tolstoy, E.; Irwin, M. J.

    2016-03-01

    We present a detailed analysis of the chemistry and kinematics of red giants in the dwarf irregular galaxy NGC 6822. Spectroscopy at ≈8500 Å was acquired for 72 red giant stars across two fields using FORS2 at the VLT. Line-of-sight extinction was individually estimated for each target star to accommodate the variable reddening across NGC 6822. The mean radial velocity was found to be = -52.8 ± 2.2 km s-1 with dispersion σv = 24.1 km s-1, in agreement with other studies. Ca II triplet equivalent widths were converted into [Fe/H] metallicities using a V magnitude proxy for surface gravity. The average metallicity was = -0.84 ± 0.04 with dispersion σ = 0.31 dex and interquartile range 0.48. Our assignment of individual reddening values makes our analysis more sensitive to spatial variations in metallicity than previous studies. We divide our sample into metal-rich and metal-poor stars; the former were found to cluster towards small radii with the metal-poor stars more evenly distributed across the galaxy. The velocity dispersion of the metal-poor stars was found to be higher than that of the metal-rich stars (σ _{v_MP}=27.4 km s-1; σ _{v_MR}=21.1 km s-1); combined with the age-metallicity relation this indicates that the older populations have either been dynamically heated during their lifetimes or were born in a less disc-like distribution than the younger stars.. The low ratio vrot/σv suggests that within the inner 10 arcmin, NGC 6822's stars are dynamically decoupled from the H I gas, and possibly distributed in a thick disc or spheroid structure.

  11. Detecting luminescence from triplet states of organic semiconductors at room temperatures using delayed electroluminescence spectroscopy

    Science.gov (United States)

    Wang, Qi; Aziz, Hany

    2014-08-01

    We demonstrate a unique approach for detecting luminescence from triplet states of organic materials in the solid state at room temperatures. The technique is based on measuring delayed electroluminescence from the material. The approach overcomes limitations of conventional spectroscopic techniques, such as the need for cooling to cryogenic temperatures, and works for a wide range of organic materials. The underlying mechanisms behind observing materials phosphorescence using this technique are studied. The results show that using a low concentration of the target material doped in a host material and a large energy differences between triplet states of target and host materials are necessary for obtaining efficient phosphorescence at room temperatures.

  12. Triplet excitation dynamics of two keto-carotenoids in n-hexane and in methanol as studied by ns flash photolysis spectroscopy

    Science.gov (United States)

    Li, Li; Hu, Feng; Chang, Yu-Qiang; Zhou, Yan; Wang, Peng; Zhang, Jian-Ping

    2015-07-01

    Siphonaxanthin and siphonein are two keto-carotenoids. Upon anthracene-sensitizing, triplet excitation dynamics of these two carotenoids were studied in n-hexane and in methanol, respectively, by ns flash photolysis spectroscopy. In n-hexane, bleaching of the ground state absorption (GSB) and the excitation triplet (3Car*) absorption were observed. In methanol, upon the decay of the 3Car*, the cation dehydrodimer of carotenoid, #[Car]2+, generated by the same rate, while an additional GSB generated synchronously, a polar solvent assisted and anthracene-sensitized mechanism was addressed based on the discussion. The environment-sensitive triplet excitation dynamics imply their potential role in photo-protection in vivo.

  13. Deriving Metallicities from Calcium Triplet Spectroscopy in combination with Near Infrared Photometry

    CERN Document Server

    Mauro, F; Geisler, D; Saviane, I; Da Costa, G S; Gormaz-Matamala, A C; Vasquez, S; Chené, A -N; Cohen, R; Dias, B

    2014-01-01

    Context. [...] One of the most efficient methods is the measurement of the equivalent width (EW) of the Calcium II Triplet (CaT), corrected for the luminosity and temperature effects via magnitude differences from the horizontal branch (HB). Methods. We use the Ks magnitude difference between the star and the reddest part of the HB (RHB) to generate reduced equivalent widths (rEW) from the datasets presented in Saviane et al. (2012) and Rutledge et al. (1997). Subsequently we calibrated these rEW against three different metellicity (met) scales: the one presented in Carretta et al. (2009), the met values given in Harris (2010) and a version of the former corrected via high-resolution spectroscopic met. Results. We calculated the calibration relations for the two datasets and the three met scales and found that they are approximately equivalent, with differences almost negligible. We compared our nIR calibrations with the corresponding optical ones, and found them to be equivalent, establishing that the lumino...

  14. Characterization of the low-temperature triplet state of chlorophyll in photosystem II core complexes: Application of phosphorescence measurements and Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Zabelin, Alexey A; Neverov, Konstantin V; Krasnovsky, Alexander A; Shkuropatova, Valentina A; Shuvalov, Vladimir A; Shkuropatov, Anatoly Ya

    2016-06-01

    Phosphorescence measurements at 77 K and light-induced FTIR difference spectroscopy at 95 K were applied to study of the triplet state of chlorophyll a ((3)Chl) in photosystem II (PSII) core complexes isolated from spinach. Using both methods, (3)Chl was observed in the core preparations with doubly reduced primary quinone acceptor QA. The spectral parameters of Chl phosphorescence resemble those in the isolated PSII reaction centers (RCs). The main spectral maximum and the lifetime of the phosphorescence corresponded to 955±1 nm and of 1.65±0.05 ms respectively; in the excitation spectrum, the absorption maxima of all core complex pigments (Chl, pheophytin a (Pheo), and β-carotene) were observed. The differential signal at 1667(-)/1628(+)cm(-1) reflecting a downshift of the stretching frequency of the 13(1)-keto C=O group of Chl was found to dominate in the triplet-minus-singlet FTIR difference spectrum of core complexes. Based on FTIR results and literature data, it is proposed that (3)Chl is mostly localized on the accessory chlorophyll that is in triplet equilibrium with P680. Analysis of the data suggests that the Chl triplet state responsible for the phosphorescence and the FTIR difference spectrum is mainly generated due to charge recombination in the reaction center radical pair P680(+)PheoD1(-), and the energy and temporal parameters of this triplet state as well as the molecular environment and interactions of the triplet-bearing Chl molecule are similar in the PSII core complexes and isolated PSII RCs.

  15. CaII Κ Imaging to Understand UV Irradiance Variability

    Indian Academy of Sciences (India)

    R. Kariyappa

    2000-09-01

    To identify and understand the underlying physical mechanisms of total solar and UV irradiance variability and to estimate the contribution of various chromospheric features to UV irradiance, detailed analysis of spatially resolved data is required. The various chromospheric features have been segregated and different parameters have been derived from CaII Κ Spectroheliograms of NSO/Sac Peak and Kodaikanal Observatory and compared with UV irradiance flux measured in MgII h and k lines by NOAA 9 satellite. The important results of this detailed analysis of CaII Κ Images of 1992 together with UV irradiance data will be discussed in this paper.

  16. Ca II Triplet Spectroscopy of Small Magellanic Cloud Red Giants. III. Abundances and Velocities for a Sample of 14 Clusters

    CERN Document Server

    Parisi, M C; Clariá, J J; Villanova, S; Marcionni, N; Sarajedini, A; Grocholski, A J

    2015-01-01

    We obtained spectra of red giants in 15 Small Magellanic Cloud (SMC) clusters in the region of the CaII lines with FORS2 on the Very Large Telescope (VLT). We determined the mean metallicity and radial velocity with mean errors of 0.05 dex and 2.6 km/s, respectively, from a mean of 6.5 members per cluster. One cluster (B113) was too young for a reliable metallicity determination and was excluded from the sample. We combined the sample studied here with 15 clusters previously studied by us using the same technique, and with 7 clusters whose metallicities determined by other authors are on a scale similar to ours. This compilation of 36 clusters is the largest SMC cluster sample currently available with accurate and homogeneously determined metallicities. We found a high probability that the metallicity distribution is bimodal, with potential peaks at -1.1 and -0.8 dex. Our data show no strong evidence of a metallicity gradient in the SMC clusters, somewhat at odds with recent evidence from CaT spectra of a lar...

  17. Time-resolved photoelectron spectroscopy of a dinuclear Pt(II) complex: Tunneling autodetachment from both singlet and triplet excited states of a molecular dianion

    Science.gov (United States)

    Winghart, Marc-Oliver; Yang, Ji-Ping; Vonderach, Matthias; Unterreiner, Andreas-Neil; Huang, Dao-Ling; Wang, Lai-Sheng; Kruppa, Sebastian; Riehn, Christoph; Kappes, Manfred M.

    2016-02-01

    Time-resolved pump-probe photoelectron spectroscopy has been used to study the relaxation dynamics of gaseous [Pt2(μ-P2O5H2)4 + 2H]2- after population of its first singlet excited state by 388 nm femtosecond laser irradiation. In contrast to the fluorescence and phosphorescence observed in condensed phase, a significant fraction of the photoexcited isolated dianions decays by electron loss to form the corresponding monoanions. Our transient photoelectron data reveal an ultrafast decay of the initially excited singlet 1A2u state and concomitant rise in population of the triplet 3A2u state, via sub-picosecond intersystem crossing (ISC). We find that both of the electronically excited states are metastably bound behind a repulsive Coulomb barrier and can decay via delayed autodetachment to yield electrons with characteristic kinetic energies. While excited state tunneling detachment (ESETD) from the singlet 1A2u state takes only a few picoseconds, ESETD from the triplet 3A2u state is much slower and proceeds on a time scale of hundreds of nanoseconds. The ISC rate in the gas phase is significantly higher than in solution, which can be rationalized in terms of changes to the energy dissipation mechanism in the absence of solvent molecules. [Pt2(μ-P2O5H2)4 + 2H]2- is the first example of a photoexcited multianion for which ESETD has been observed following ISC.

  18. Confirming the intrinsic abundance spread in the globular cluster NGC 6273 (M19) with calcium triplet spectroscopy

    Science.gov (United States)

    Yong, David; Da Costa, Gary S.; Norris, John E.

    2016-08-01

    We present metallicities for red giant stars in the globular cluster NGC 6273 based on intermediate resolution GMOS-S spectra of the calcium triplet region. For the 42 radial velocity members with reliable calcium triplet line strength measurements, we obtain metallicities, [Fe/H], using calibrations established from standard globular clusters. We confirm the presence of an intrinsic abundance dispersion identified by Johnson et al. The total range in [Fe/H] is ˜1.0 dex and after taking into account the measurement errors, the intrinsic abundance dispersion is σint[Fe/H] = 0.17 dex. Among the Galactic globular clusters, the abundance dispersion in NGC 6273 is only exceeded by ω Cen, which is regarded as the remnant of a disrupted dwarf galaxy, and M54, which is the nuclear star cluster of the Sagittarius dwarf galaxy. If these three globular clusters share the same formation mechanism, then NGC 6273 may also be the remnant nucleus of a disrupted dwarf galaxy.

  19. Confirming the intrinsic abundance spread in the globular cluster NGC 6273 (M 19) with calcium triplet spectroscopy

    CERN Document Server

    Yong, David; Norris, John E

    2016-01-01

    We present metallicities for red giant stars in the globular cluster NGC 6273 based on intermediate resolution GMOS-S spectra of the calcium triplet region. For the 42 radial velocity members with reliable calcium triplet line strength measurements, we obtain metallicities, [Fe/H], using calibrations established from standard globular clusters. We confirm the presence of an intrinsic abundance dispersion identified by Johnson et al. (2015). The total range in [Fe/H] is ~1.0 dex and after taking into account the measurement errors, the intrinsic abundance dispersion is \\sigma[Fe/H] = 0.17 dex. Among the Galactic globular clusters, the abundance dispersion in NGC 6273 is only exceeded by omega Cen, which is regarded as the remnant of a disrupted dwarf galaxy, and M 54, which is the nuclear star cluster of the Sagittarius dwarf galaxy. If these three globular clusters share the same formation mechanism, then NGC 6273 may also be the remnant nucleus of a disrupted dwarf galaxy.

  20. Vibrational circular dichroism spectroscopy of a spin-triplet bis-(biuretato) cobaltate(III) coordination compound with low-lying electronic transitions

    DEFF Research Database (Denmark)

    Johannessen, Christian; Thulstrup, Peter W.

    2007-01-01

    . The spectroscopic results were compared to measurements performed on the free ligand and to theoretical calculations using density functional theory (B3LYP/TZVP). The results of the VCD analysis of the coordination compound identified an electronic, dipole-forbidden, magnetic dipole-allowed low-lying d-d transition......Vibrational absorption (VA) and vibrational circular dichroism (VCD) spectroscopy was applied in the analysis of vibrational and low lying electronic transitions of a triplet ground state cobalt(III) coordination compound. The spectroscopic measurements were performed on the tetrabutylammonium salt...... located in the mid infrared, as well as several amide stretch transitions located in the fingerprint region (1800-1100 cm(-1)), in both the liquid and solid phase. VCD signals were found to be 5-10 times higher than expected, indicating enhancement of the vibrational CD signals, caused by coupling...

  1. Time-resolved photoelectron spectroscopy of a dinuclear Pt(II) complex: Tunneling autodetachment from both singlet and triplet excited states of a molecular dianion

    Energy Technology Data Exchange (ETDEWEB)

    Winghart, Marc-Oliver, E-mail: marc-oliver.winghart@kit.edu; Unterreiner, Andreas-Neil [Institute of Physical Chemistry, Karlsruhe Institute of Technology, P.O. Box 6980, 76049 Karlsruhe (Germany); Yang, Ji-Ping [Institute of Physical Chemistry, Karlsruhe Institute of Technology, P.O. Box 6980, 76049 Karlsruhe (Germany); School of Sciences, Hefei University of Technology, Hefei 230009 (China); Vonderach, Matthias [Centre for Proteome Research, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB (United Kingdom); Huang, Dao-Ling; Wang, Lai-Sheng [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States); Kruppa, Sebastian; Riehn, Christoph [Fachbereich Chemie und Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, Erwin-Schrödinger-Str. 52–54, 67663 Kaiserslautern (Germany); Kappes, Manfred M., E-mail: manfred.kappes@kit.edu [Institute of Physical Chemistry, Karlsruhe Institute of Technology, P.O. Box 6980, 76049 Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe (Germany)

    2016-02-07

    Time-resolved pump-probe photoelectron spectroscopy has been used to study the relaxation dynamics of gaseous [Pt{sub 2}(μ-P{sub 2}O{sub 5}H{sub 2}){sub 4} + 2H]{sup 2−} after population of its first singlet excited state by 388 nm femtosecond laser irradiation. In contrast to the fluorescence and phosphorescence observed in condensed phase, a significant fraction of the photoexcited isolated dianions decays by electron loss to form the corresponding monoanions. Our transient photoelectron data reveal an ultrafast decay of the initially excited singlet {sup 1}A{sub 2u} state and concomitant rise in population of the triplet {sup 3}A{sub 2u} state, via sub-picosecond intersystem crossing (ISC). We find that both of the electronically excited states are metastably bound behind a repulsive Coulomb barrier and can decay via delayed autodetachment to yield electrons with characteristic kinetic energies. While excited state tunneling detachment (ESETD) from the singlet {sup 1}A{sub 2u} state takes only a few picoseconds, ESETD from the triplet {sup 3}A{sub 2u} state is much slower and proceeds on a time scale of hundreds of nanoseconds. The ISC rate in the gas phase is significantly higher than in solution, which can be rationalized in terms of changes to the energy dissipation mechanism in the absence of solvent molecules. [Pt{sub 2}(μ-P{sub 2}O{sub 5}H{sub 2}){sub 4} + 2H]{sup 2−} is the first example of a photoexcited multianion for which ESETD has been observed following ISC.

  2. Time sequence spectroscopy of AW UMa. The 518 nm Mg I triplet region analyzed with Broadening Functions

    CERN Document Server

    Rucinski, Slavek M

    2014-01-01

    High resolution spectroscopic observations of AW UMa, obtained on three consecutive nights with the median time resolution of 2.1 minutes, have been analyzed using the Broadening Functions method in the spectral window of 22.75 nm around the 518 nm Mg I triplet region. Doppler images of the system reveal the presence of vigorous mass motions within the binary system. The ample evidence of a non-solid-body velocity field puts into question the contact-binary model based on solid-body equipotentials. AW UMa is a semi-detached binary; the mass transfer takes place from the more massive to the less massive component. The primary, a fast-rotating star with Vsin i = 181.4 km/s, is covered by inhomogeneities: very slowly drifting spots and a dense network of ripples more closely participating in its rotation. The spectral lines of the primary show an additional broadening component (called the "pedestal") which originates either in the equatorial regions which rotate faster than the rest of the star by about 50 km/s...

  3. R-matrix calculations of triplet gerade states of molecular hydrogen and their use for high-resolution spectroscopy

    Science.gov (United States)

    Oueslati, H.; Argoubi, F.; Bezzaouia, S.; Telmini, M.; Jungen, Ch.

    2014-03-01

    A variational R-matrix approach combined with multichannel quantum defect theory is used for a computational study of triplet gerade states of H2. Electron-ion reaction (quantum defect) matrices are calculated as functions of internuclear distance and energy for the bound and continuum ranges including singly and doubly excited configurations built on the 1σg (X+2Σg+) and 1σu (A+2Σu+) core states of the H2+ ion. It is shown how these matrices can be reduced to effective quantum defect functions adapted to the analysis of high-resolution spectra in the bound range. These R-matrix effective quantum defects are finally adjusted to the available experimental data [Sprecher et al., J. Phys. Chem. A 117, 9462 (2013), 10.1021/jp311793t], producing agreement with experiment to within 0.5 cm-1, nearly as good as obtained by Sprecher et al. In addition, the R-matrix calculations predict the evolution of the quantum defects for higher energies, in a range extending far into the electronic continuum.

  4. New constraints on the chemical evolution of the dwarf spheroidal galaxy LeoI from VLT spectroscopy

    CERN Document Server

    Gullieuszik, M; Saviane, I; Rizzi, L

    2009-01-01

    (Abridged) We present the spectroscopy of red giant stars in the dwarf spheroidal galaxy LeoI, aimed at further constraining its chemical enrichment history. Intermediate-resolution spectroscopy in the CaII triplet spectral region was obtained for 54 stars in LeoI using FORS2 at the ESO Very Large Telescope. The equivalent widths of CaII triplet lines were used to derive the metallicities of the target stars on the [Fe/H] scale of Carretta & Gratton, as well as on a scale tied to the global metal abundance, [M/H]. The metallicity distribution function for LeoI stars is confirmed to be very narrow, with mean value [M/H]~-1.2 and intrinsic dispersion, sigma_[M/H]=0.08. We find a few metal-poor stars (whose metallicity values depend on the adopted extrapolation of the existing calibrations), but in no case are stars more metal-poor than [Fe/H]=-2.6. Our measurements provide a hint of a shallow metallicity gradient of -0.27 dex/Kpc among LeoI red giants. By combining the metallicities of the target stars with...

  5. CA II TRIPLET SPECTROSCOPY OF SMALL MAGELLANIC CLOUD RED GIANTS. III. ABUNDANCES AND VELOCITIES FOR A SAMPLE OF 14 CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, M. C.; Clariá, J. J.; Marcionni, N. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba, CP 5000 (Argentina); Geisler, D.; Villanova, S. [Departamento de Astronomía, Universidad de Concepción Casilla 160-C, Concepción (Chile); Sarajedini, A. [Department of Astronomy, University of Florida P.O. Box 112055, Gainesville, FL 32611 (United States); Grocholski, A. J., E-mail: celeste@oac.uncor.edu, E-mail: claria@oac.uncor.edu, E-mail: nmarcionni@oac.uncor.edu, E-mail: dgeisler@astro-udec.cl, E-mail: svillanova@astro-udec.cl, E-mail: ata@astro.ufl.edu, E-mail: grocholski@phys.lsu.edu [Department of Physics and Astronomy, Louisiana State University 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States)

    2015-05-15

    We obtained spectra of red giants in 15 Small Magellanic Cloud (SMC) clusters in the region of the Ca ii lines with FORS2 on the Very Large Telescope. We determined the mean metallicity and radial velocity with mean errors of 0.05 dex and 2.6 km s{sup −1}, respectively, from a mean of 6.5 members per cluster. One cluster (B113) was too young for a reliable metallicity determination and was excluded from the sample. We combined the sample studied here with 15 clusters previously studied by us using the same technique, and with 7 clusters whose metallicities determined by other authors are on a scale similar to ours. This compilation of 36 clusters is the largest SMC cluster sample currently available with accurate and homogeneously determined metallicities. We found a high probability that the metallicity distribution is bimodal, with potential peaks at −1.1 and −0.8 dex. Our data show no strong evidence of a metallicity gradient in the SMC clusters, somewhat at odds with recent evidence from Ca ii triplet spectra of a large sample of field stars. This may be revealing possible differences in the chemical history of clusters and field stars. Our clusters show a significant dispersion of metallicities, whatever age is considered, which could be reflecting the lack of a unique age–metallicity relation in this galaxy. None of the chemical evolution models currently available in the literature satisfactorily represents the global chemical enrichment processes of SMC clusters.

  6. Radial velocities and metallicities from infrared Ca II triplet spectroscopy of open clusters II. Berkeley 23, King 1, NGC 559, NGC 6603 and NGC 7245

    CERN Document Server

    Carrera, R; Ospina, N; Balaguer-Nuñez, L; Jordi, C; Monteagudo, L

    2015-01-01

    Context: Open clusters are key to studying the formation and evolution of the Galactic disc. However, there is a deficiency of radial velocity and chemical abundance determinations for open clusters in the literature. Aims: We intend to increase the number of determinations of radial velocities and metallicities from spectroscopy for open clusters. Methods: We acquired medium-resolution spectra (R~8000) in the infrared region Ca II triplet lines (~8500 AA) for several stars in five open clusters with the long-slit IDS spectrograph on the 2.5~m Isaac Newton Telescope (Roque de los Muchachos Observatory, Spain). Radial velocities were obtained by cross-correlation fitting techniques. The relationships available in the literature between the strength of infrared Ca II lines and metallicity were also used to derive the metallicity for each cluster. Results: We obtain = 48.6+/-3.4, -58.4+/-6.8, 26.0+/-4.3 and -65.3+/-3.2 km s-1 for Berkeley 23, NGC 559, NGC 6603 and NGC 7245, respectively. We found [Fe/H] =-0.25+...

  7. Spectroscopy of {sup 39}K{sup 85}Rb triplet excited states using ultracold a {sup 3}{sigma}{sup +} state molecules formed by photoassociation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J T; Wang, D; Eyler, E E; Gould, P L; Stwalley, W C [Physics Department, University of Connecticut, Storrs, CT 06269 (United States)], E-mail: w.stwalley@uconn.edu, E-mail: kimjt@chosun.ac.kr

    2009-05-15

    Convenient state-selective detection methods are proposed for exploring triplet Rydberg states from the metastable a {sup 3}{sigma}{sup +} state of ultracold KRb molecules by resonance-enhanced two-photon ionization and time-of-flight (TOF) mass spectroscopy. This would allow the first accurate determination of the ionization potential. Particularly suitable resonant intermediate states include the 2 {sup 3}{pi} {sub {omega}}, 3 {sup 3}{sigma}{sup +} and 4 {sup 3}{sigma}{sup +} states, and we report spectroscopic studies of these states. For the 2 {sup 3}{pi} {sub {omega}} state, the spin-orbit components ({omega} = 0{sup +}, 0{sup -}, 1 and 2) have been investigated and a shallow long-range state (5(0{sup +})) at {approx} 9.3 A has been observed. We compare our observations of these three states with predictions based on ab initio potential energy curves. Such studies may also permit the direct observation of autoionizing resonances leading to efficient formation of low-lying rovibrational levels of the {sup 2}{sigma}{sup +} ground state of KRb{sup +}, ideally in the v{sup +}= 0, N{sup +}= 0 level.

  8. Vibrational circular dichroism spectroscopy of a spin-triplet bis-(biuretato) cobaltate(III) coordination compound with low-lying electronic transitions.

    Science.gov (United States)

    Johannessen, Christian; Thulstrup, Peter W

    2007-03-14

    Vibrational absorption (VA) and vibrational circular dichroism (VCD) spectroscopy was applied in the analysis of vibrational and low lying electronic transitions of a triplet ground state cobalt(III) coordination compound. The spectroscopic measurements were performed on the tetrabutylammonium salt of (6S,7S)-1,3,5,8,10,12-hexaaza-2,4,9,11-tetraoxo-6,7-diphenyl-dodecanato(4-)cobaltate(III) in DMSO solution and in potassium bromide pellets. The chiral anion exhibits an unusual geometry for cobalt(III), being four-coordinate, planar, and paramagnetic with an intermediate spin state. The spectroscopic results were compared to measurements performed on the free ligand and to theoretical calculations using density functional theory (B3LYP/TZVP). The results of the VCD analysis of the coordination compound identified an electronic, dipole-forbidden, magnetic dipole-allowed low-lying d-d transition located in the mid infrared, as well as several amide stretch transitions located in the fingerprint region (1800-1100 cm(-1)), in both the liquid and solid phase. VCD signals were found to be 5-10 times higher than expected, indicating enhancement of the vibrational CD signals, caused by coupling of the vibrational transitions with the close-lying electronic transition.

  9. Toward Triplet Ground State NaLi Molecules

    Science.gov (United States)

    Ebadi, Sepehr; Jamison, Alan; Rvachov, Timur; Jing, Li; Son, Hyungmok; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2016-05-01

    The NaLi molecule is expected to have a long lifetime in the triplet ground-state due to its fermionic nature, large rotational constant, and weak spin-orbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. We have mapped the excited state NaLi triplet potential by means of photoassociation spectroscopy. We report on this and our further progress toward the creation of the triplet ground-state molecules using STIRAP. NSF, ARO-MURI, Samsung, NSERC.

  10. Direct observation of triplet energy transfer from semiconductor nanocrystals.

    Science.gov (United States)

    Mongin, Cédric; Garakyaraghi, Sofia; Razgoniaeva, Natalia; Zamkov, Mikhail; Castellano, Felix N

    2016-01-22

    Triplet excitons are pervasive in both organic and inorganic semiconductors but generally remain confined to the material in which they originate. We demonstrated by transient absorption spectroscopy that cadmium selenide semiconductor nanoparticles, selectively excited by green light, engage in interfacial Dexter-like triplet-triplet energy transfer with surface-anchored polyaromatic carboxylic acid acceptors, extending the excited-state lifetime by six orders of magnitude. Net triplet energy transfer also occurs from surface acceptors to freely diffusing molecular solutes, further extending the lifetime while sensitizing singlet oxygen in an aerated solution. The successful translation of triplet excitons from semiconductor nanoparticles to the bulk solution implies that such materials are generally effective surrogates for molecular triplets. The nanoparticles could thereby potentially sensitize a range of chemical transformations that are relevant for fields as diverse as optoelectronics, solar energy conversion, and photobiology. PMID:26798011

  11. Triplet exciton dynamics

    International Nuclear Information System (INIS)

    Results are presented of electron spin echo experiments combined with laser flash excitation on triplet states of aromatic molecules. Some of the theoretical and experimental aspects of the photoexcited triplet state are discussed in detail and the electron spin echo spectrometers and laser systems are described. All the experiments described in this thesis were performed at liquid helium temperatures. An account is given of the ESE experiments performed on the photoexcited, non-radiative, triplet state of pentacene in napthalene. This is an example of the ESE technique being used to ascertain the zero-field splitting parameters, the populating and depopulating rates, and the orientation of the pentacene molecules in the naphthalene host. A combination of high resolution laser flash excitation and electron-spin echoes in zero-magnetic field allowed the author to observe directly k(vector)→k(vector)' exciton scattering processes in the one-dimensional triplet excitons in tetrachlorobenzene for the first time. Additional experimental data about exciton scattering is provided and a study of the orientational dependence of the spin-lattice relaxation of the triplet excitons in an external magnetic field is described. (Auth.)

  12. Ca II Triplet Spectroscopy of Small Magellanic Cloud Red Giants. IV. Abundances for a Large Sample of Field Stars and Comparison with the Cluster Sample

    Science.gov (United States)

    Parisi, M. C.; Geisler, D.; Carraro, G.; Clariá, J. J.; Villanova, S.; Gramajo, L. V.; Sarajedini, A.; Grocholski, A. J.

    2016-09-01

    This paper represents a major step forward in the systematic and homogeneous study of Small Magellanic Cloud (SMC) star clusters and field stars carried out by applying the calcium triplet technique. We present in this work the radial velocity and metallicity of approximately 400 red giant stars in 15 SMC fields, with typical errors of about 7 km s-1 and 0.16 dex, respectively. We added to this information our previously determined metallicity values for 29 clusters and approximately 350 field stars using the identical techniques. Using this enlarged sample, we analyze the metallicity distribution and gradient in this galaxy. We also compare the chemical properties of the clusters and of their surrounding fields. We find a number of surprising results. While the clusters, taken as a whole, show no strong evidence for a metallicity gradient (MG), the field stars exhibit a clear negative gradient in the inner region of the SMC, consistent with the recent results of Dobbie et al. For distances to the center of the galaxy less than 4°, field stars show a considerably smaller metallicity dispersion than that of the clusters. However, in the external SMC regions, clusters and field stars exhibit similar metallicity dispersions. Moreover, in the inner region of the SMC, clusters appear to be concentrated in two groups: one more metal-poor and another more metal-rich than field stars. Individually considered, neither cluster group presents an MG. Most surprisingly, the MG for both stellar populations (clusters and field stars) appears to reverse sign in the outer regions of the SMC. The difference between the cluster metallicity and the mean metallicity of the surrounding field stars turns out to be a strong function of the cluster metallicity. These results could be indicating different chemical evolution histories for these two SMC stellar populations. They could also indicate variations in the chemical behavior of the SMC in its internal and external regions.

  13. CaII Absorbers in the Sloan Digital Sky Survey: Element Abundances and Dust

    CERN Document Server

    Sardane, Gendith M; Rao, Sandhya M

    2015-01-01

    We present measurements of element abundance ratios and dust in CaII~absorbers identified in SDSS DR7+DR9. In an earlier paper we formed a statistical sample of 435 CaII absorbers and postulated that their statistical properties might be representative of at least two populations of absorbers. Here we show that if the absorbers are roughly divided into two subsamples with CaII rest equivalent widths larger and smaller than $W_0^{\\lambda 3934} = 0.7$ \\AA, they are then representative of two physically different populations. Comparisons of abundance ratios between the two CaII absorber populations indicate that the weaker $W_0^{\\lambda 3934}$ absorbers have properties consistent with halo-type gas, while the stronger absorbers have properties intermediate between halo- and disk-type gas. We also show that, on average, the dust extinction properties of the overall sample is consistent with a LMC or SMC dust law, and the stronger absorbers are nearly 6 times more reddened than their weaker counterparts. The absor...

  14. Time-resolved resonance Raman spectroscopy of 1,3,5-hexatrienes in the lowest excited triplet state. The potential energy surface in T1

    OpenAIRE

    Wilbrandt, R; Langkilde, F.W.; Brouwer, A.M.; Negri, F; Orlandi, G.

    1990-01-01

    Time-resolved resonance Raman spectroscopy is applied to the study of the T1 state of 1,3,5-hexatriene and deuteriated and methylated derivatives in solution. The technique is described briefly. The experimentally obtained resonance Raman spectra are discussed in the light of theoretical Quantum Chemical Force Field calculations. Implications for the potential energy surface of the T1 state are discussed.

  15. Phasic Triplet Markov Chains.

    Science.gov (United States)

    El Yazid Boudaren, Mohamed; Monfrini, Emmanuel; Pieczynski, Wojciech; Aïssani, Amar

    2014-11-01

    Hidden Markov chains have been shown to be inadequate for data modeling under some complex conditions. In this work, we address the problem of statistical modeling of phenomena involving two heterogeneous system states. Such phenomena may arise in biology or communications, among other fields. Namely, we consider that a sequence of meaningful words is to be searched within a whole observation that also contains arbitrary one-by-one symbols. Moreover, a word may be interrupted at some site to be carried on later. Applying plain hidden Markov chains to such data, while ignoring their specificity, yields unsatisfactory results. The Phasic triplet Markov chain, proposed in this paper, overcomes this difficulty by means of an auxiliary underlying process in accordance with the triplet Markov chains theory. Related Bayesian restoration techniques and parameters estimation procedures according to the new model are then described. Finally, to assess the performance of the proposed model against the conventional hidden Markov chain model, experiments are conducted on synthetic and real data. PMID:26353069

  16. Formation of ultracold 7Li85Rb molecules in the lowest triplet electronic state by photoassociation and their detection by ionization spectroscopy

    International Nuclear Information System (INIS)

    We report the formation of ultracold 7Li85Rb molecules in the a3Σ+ electronic state by photoassociation (PA) and their detection via resonantly enhanced multiphoton ionization (REMPI). With our dual-species Li and Rb magneto-optical trap apparatus, we detect PA resonances with binding energies up to ∼62 cm−1 below the 7Li 2s 2S1/2 + 85Rb 5p 2P1/2 asymptote. In addition, we use REMPI spectroscopy to probe the a3Σ+ state and excited electronic 33Π and 43Σ+ states and identify a3Σ+ (v″ = 7–13), 33Π (vΠ′ = 0–10), and 43Σ+ (vΣ′ = 0–5) vibrational levels. Our line assignments agree well with ab initio calculations. These preliminary spectroscopic studies on previously unobserved electronic states are crucial to discovering transition pathways for transferring ultracold LiRb molecules created via PA to deeply bound rovibrational levels of the electronic ground state

  17. Formation of ultracold (7)Li(85)Rb molecules in the lowest triplet electronic state by photoassociation and their detection by ionization spectroscopy.

    Science.gov (United States)

    Altaf, Adeel; Dutta, Sourav; Lorenz, John; Pérez-Ríos, Jesús; Chen, Yong P; Elliott, D S

    2015-03-21

    We report the formation of ultracold (7)Li(85)Rb molecules in the a(3)Σ(+) electronic state by photoassociation (PA) and their detection via resonantly enhanced multiphoton ionization (REMPI). With our dual-species Li and Rb magneto-optical trap apparatus, we detect PA resonances with binding energies up to ∼62 cm(-1) below the (7)Li 2s (2)S1/2 + (85)Rb 5p (2)P1/2 asymptote. In addition, we use REMPI spectroscopy to probe the a(3)Σ(+) state and excited electronic 3(3)Π and 4(3)Σ(+) states and identify a(3)Σ(+) (v″ = 7-13), 3(3)Π (vΠ' = 0-10), and 4(3)Σ(+) (vΣ' = 0-5) vibrational levels. Our line assignments agree well with ab initio calculations. These preliminary spectroscopic studies on previously unobserved electronic states are crucial to discovering transition pathways for transferring ultracold LiRb molecules created via PA to deeply bound rovibrational levels of the electronic ground state. PMID:25796252

  18. Retinopathy of Prematurity in Triplets

    Directory of Open Access Journals (Sweden)

    Mehmet Ali Şekeroğlu

    2016-06-01

    Full Text Available Objectives: To investigate the incidence, severity and risk factors of retinopathy of prematurity (ROP in triplets. Materials and Methods: The medical records of consecutive premature triplets who had been screened for ROP in a single maternity hospital were analyzed and presence and severity of ROP; birth weight, gender, gestational age of the infant; route of delivery and the mode of conception were recorded. Results: A total of 54 triplets (40 males, 14 females who were screened for ROP between March 2010 and February 2013 were recruited for the study. All triplets were delivered by Caesarean section and 36 (66.7% were born following an assisted conception. During follow-up, seven (13% of the infants developed ROP of any stage and two (3.7% required laser photocoagulation. The mean gestational age of triplets with ROP was 27.6±1.5 (27-31 weeks whereas it was 32.0±1.5 (30-34 weeks in those without ROP (p=0.002. The mean birth weights of triplets with and without ROP were 1290.0±295.2 (970-1600 g and 1667.5±222.2 (1130-1960 g, respectively (p<0.001. The presence of ROP was not associated with gender (p=0.358 or mode of conception (p=0.674. Conclusion: ROP in triplets seems to be mainly related to low gestational age and low birth weight. Further prospective randomized studies are necessary to demonstrate risk factors of ROP in triplets and to determine if and how gemelarity plays a role in the development of ROP.

  19. Observation of Two Triplet-Pair Intermediates in Singlet Exciton Fission.

    Science.gov (United States)

    Pensack, Ryan D; Ostroumov, Evgeny E; Tilley, Andrew J; Mazza, Samuel; Grieco, Christopher; Thorley, Karl J; Asbury, John B; Seferos, Dwight S; Anthony, John E; Scholes, Gregory D

    2016-07-01

    Singlet fission is an excitation multiplication process in molecular systems that can circumvent energy losses and significantly boost solar cell efficiencies; however, the nature of a critical intermediate that enables singlet fission and details of its evolution into multiple product excitations remain obscure. We resolve the initial sequence of events comprising the fission of a singlet exciton in solids of pentacene derivatives using femtosecond transient absorption spectroscopy. We propose a three-step model of singlet fission that includes two triplet-pair intermediates and show how transient spectroscopy can distinguish initially interacting triplet pairs from those that are spatially separated and noninteracting. We find that the interconversion of these two triplet-pair intermediates is limited by the rate of triplet transfer. These results clearly highlight the classical kinetic model of singlet fission and expose subtle details that promise to aid in resolving problems associated with triplet extraction. PMID:27281713

  20. Triplets pass their pressure test

    CERN Multimedia

    2007-01-01

    All the LHC inner triplets have now been repaired and are in position. The first ones have passed their pressure tests with flying colours. The repaired inner triplet at LHC Point 1, right side (1R). Ranko Ostojic (on the right), who headed the team responsible for repairing the triplets, shows the magnet to Robert Zimmer, President of the University of Chicago and of Fermi Research Alliance, who visited CERN on 20th August.Three cheers for the triplets! All the LHC inner triplets have now been repaired and are in position in the tunnel. Thanks to the mobilisation of a multidisciplinary team from CERN and Fermilab, assisted by the KEK Laboratory and the Lawrence Berkeley National Laboratory (LBNL), a solution has been found, tested, validated and applied. At the end of March this year, one of the inner triplets at Point 5 failed to withstand a pressure test. A fault was identified in the supports of two out of the three quadruple magne...

  1. Fetomaternal outcome in triplet pregnancy

    International Nuclear Information System (INIS)

    To determine maternal outcome as antenatal and postnatal complications and neonatal outcome as birth weight, morbidity and mortality in triplet gestation. All the patients with triplet pregnancy beyond 28 weeks gestation, who delivered at the study place during above period were included in the study. The primary outcome measures were frequency of maternal complications and neonatal birth, weight and morbidity. Secondary outcome measures included the frequency of assisted conception in the studied cohart. Eighteen women had triplet pregnancy beyond 28 weeks. Nine were booked, 6 non-booked and 3 of them were referred. Mean duration of gestation was 237.8 days (33.8 weeks). The antenatal complications were preterm delivery in 50%, hypertension in 50%, anemia in 44.4% and obstetric cholestasis in 5.6%. Eight patients (44.4%) suffered postpartum hemorrhage. One patient had peripartum hysterectomy and later expired in intensive care unit after three weeks. Maternal mortality ratio was 5.6%. Fifty five percent women had induction of ovulation with Clomiphene, while none had In Vitro Fertilization (IVF) or Intracytoplasmic Insemination (ICSI) or received gonadotrophins. Fifteen sets of triplets were delivered abdominally. Mean birth weights of 1st, 2nd and 3rd triplet were 1651, 1640 and 1443 grams respectively. Five sets of triplets (27.8%) had more than 25% discordance for birth weight. The mean Apgar scores of the babies at 1 and 10 minutes after birth were 6.0 and 8.0, 5.6 and 7.5; and 5.2 and 7.0 respectively. Of the 54 infants, 18 required Neonatal Intensive Care Unit (NICU) admission and 14 were admitted in nursery. Two died shortly after birth. Total perinatal mortalities were 13 including 4 cases of intra-uterine demise. Three babies suffered from jaundice, 7 had sepsis and 8 had respiratory distress syndrome. Triplet gestation had a high rate of fetomaternal complications. Majority had history of assisted conception. (author)

  2. SUGRA interactions within flavor triplets

    CERN Document Server

    Towe, J

    2005-01-01

    A specific new quark permits that flavor generations constitute a representation of the 3-dimensional SU(3) symmetry that characterizes the Z(3) orbifold. In this context, color and supergravity bind triplets and 4-tuplets into composite fields of spin 3/2 and spin 2; and the symmetry E(8) that characterizes (the observable sector of) 10-spacetime is interpreted as having reduced to SU(5)XSU(3), where SU(3) refers to the 3-dimensional symmetry described above and SU(5) consists of colors and of isotopic spin classes that are devoid of color and hypercharge. In this context, supergravity interactions occur to color bound quarks that are experiencing asymptotic freedom within triplets. Quark-lepton transitions are produced, but quickly reverse, preserving the triplets. The symmetry consisting of six quark classes and six lepton classes is also maintained because the predicted quark is an anomalous, left-handed version of the strange quark.

  3. Development of a Triplet-Triplet Absorption Ruler: DNA- and Chromatin-Mediated Drug Molecule Release from a Nanosurface.

    Science.gov (United States)

    Chakraborty, Sudeshna Das; Sau, Abhishek; Kuznetsov, Denis V; Banerjee, Amrita; Bardhan, Munmun; Bhattacharya, Maireyee; Dasgupta, Dipak; Basu, Samita; Senapati, Dulal

    2016-07-14

    Triplet-triplet (T-T) absorption spectroscopy has been used successfully as a molecular ruler to understand the actual release process of sanguinarine as a drug molecule from a gold nanoparticle surface in the presence of cell components, that is, DNA and chromatin. The obtained results have been verified by fluorescence and surface-enhanced Raman spectroscopy (SERS), and a plausible explanation has been put forward to describe the underestimation and overestimation of the percentage (%) of the release of drug molecules measured by fluorescence- and SERS-based techniques, respectively, over the highlighted T-T absorption spectroscopy. Because of the intrinsic nature of absorption, the reported T-T absorption spectroscopic assay overpowers fluorescence- and SERS-based assays, which are limited by the long-range interaction and nonlinear dependence of the concentration of analytes, respectively. PMID:27284775

  4. Topological Aspects of Triplet Superconductors

    Institute of Scientific and Technical Information of China (English)

    REN Ji-Rong; XU Dong-Hui; ZHANG Xin-Hui; LI Ran

    2007-01-01

    In this paper, using the φ-mapping theory, it is shown that two kinds of topological defects, i.e., the vortex lines and the monopoles exist in the helical configuration of magnetic field in triplet superconductors. And the inner topological structure of these defects is studied. Because the knot solitons in the triplet superconductors are characterized by the Hopf invariant, we also establish a relationship between the Hopf invariant and the linking number of knots family,and reveal the inner topological structure of the Hopf invariant.

  5. Metallophthalocyanines as triplet sensitizers for highly efficient photon upconversion based on sensitized triplet-triplet annihilation.

    Science.gov (United States)

    Han, J L; You, J; Yonemura, H; Yamada, S; Wang, S R; Li, X G

    2016-08-01

    Soluble palladium and platinum phthalocyanines with coumarin moieties were synthesized with Q bands in the red and near-IR regions, in which the molar extinction coefficients were up to 1.01 × 10(5) cm(-1) mol(-1). These metallophthalocyanines were coupled with rubrene and applied in photon upconversion systems based on triplet-triplet annihilation. The highest upconversion efficiency of the palladium phthalocyanine was 5.6%, which is higher than that of the platinum phthalocyanine-rubrene system. The larger molar extinction coefficient resulted in high upconversion capability (>10(5) cm(-1) mol(-1)) and low saturation incident power (<20 mW cm(-2)). PMID:27431880

  6. Ca(II) Binding Regulates and Dominates the Reactivity of a Transition-Metal-Ion-Dependent Diesterase from Mycobacterium tuberculosis.

    Science.gov (United States)

    Pedroso, Marcelo M; Larrabee, James A; Ely, Fernanda; Gwee, Shuhui E; Mitić, Nataša; Ollis, David L; Gahan, Lawrence R; Schenk, Gerhard

    2016-01-18

    The diesterase Rv0805 from Mycobacterium tuberculosis is a dinuclear metallohydrolase that plays an important role in signal transduction by controlling the intracellular levels of cyclic nucleotides. As Rv0805 is essential for mycobacterial growth it is a promising new target for the development of chemotherapeutics to treat tuberculosis. The in vivo metal-ion composition of Rv0805 is subject to debate. Here, we demonstrate that the active site accommodates two divalent transition metal ions with binding affinities ranging from approximately 50 nm for Mn(II) to about 600 nm for Zn(II) . In contrast, the enzyme GpdQ from Enterobacter aerogenes, despite having a coordination sphere identical to that of Rv0805, binds only one metal ion in the absence of substrate, thus demonstrating the significance of the outer sphere to modulate metal-ion binding and enzymatic reactivity. Ca(II) also binds tightly to Rv0805 (Kd ≈40 nm), but kinetic, calorimetric, and spectroscopic data indicate that two Ca(II) ions bind at a site different from the dinuclear transition-metal-ion binding site. Ca(II) acts as an activator of the enzymatic activity but is able to promote the hydrolysis of substrates even in the absence of transition-metal ions, thus providing an effective strategy for the regulation of the enzymatic activity.

  7. Observational Searches for Chromospheric -Mode Oscillations from CaII H-Line Observations

    Indian Academy of Sciences (India)

    R. Kariyappa; L. Damé; K. M. Hiremath

    2006-06-01

    We have used a high spatial and temporal resolution of long time sequence of spectra in CaII H-line obtained at the Vacuum Tower Telescope (VTT) of the Sacramento Peak Observatory on a quiet region at the center of the solar disk over a large number of bright points and network elements to search for atmospheric (chromospheric) -mode oscillations. An important parameter of the H-line profile, intensity at H2V(IH2V), has been derived from a large number of line profiles. We derived the light curves of all the bright points and network elements. The light curves represent the main pulse with large intensity amplitude and followed by several follower pulses with lower intensity amplitudes. The light curves of these bright points would give an impression that one can as well draw curves towards and away from the highest peak (main pulse) showing an exponential growth and decay of the amplitudes. An exponential decaying function has been fitted for all the light curves of the bright points to determine the damping time of the modes that are more or less the same, and one value of the coefficient of exponent can represent reasonably well the decay for all the cases. The FFT analysis of temporal variation of both the bright points and the network elements indicates around 10-min periodicity. We speculate that this longer period of oscillation may be related to chromospheric -mode oscillations.

  8. Interplay between singlet and triplet excited states in a conformationally locked donor–acceptor dyad

    KAUST Repository

    Filatov, Mikhail A.

    2015-10-13

    The synthesis and photophysical characterization of a palladium(II) porphyrin – anthracene dyad bridged via short and conformationally rigid bicyclo[2.2.2]octadiene spacer were achieved. A spectroscopic investigation of the prepared molecule in solution has been undertaken to study electronic energy transfer in excited singlet and triplet states between the anthracene and porphyrin units. By using steady-state and time-resolved photoluminescence spectroscopy it was shown that excitation of the singlet excited state of the anthracene leads to energy transfer to the lower-lying singlet state of porphyrin. Alternatively, excitation of the porphyrin followed by intersystem crossing to the triplet state leads to very fast energy transfer to the triplet state of anthracene. The rate of this energy transfer has been determined by transient absorption spectroscopy. Comparative studies of the dynamics of triplet excited states of the dyad and reference palladium octaethylporphyrin (PdOEP) have been performed.

  9. Tough Decisions for Premature Triplets.

    Science.gov (United States)

    Hurst, Ashley; Vergales, Brooke D; Paget-Brown, Alix; Mercurio, Mark; Lantos, John D

    2016-02-01

    When infants are born at the borderline of viability, doctors and parents have to make tough decisions about whether to institute intensive care or provide only palliative care. Often, these decisions are made in moments of profound emotional turmoil, and parents receive different information from different health professionals. Communication can become garbled. It may be difficult to tell when and whether the patient's clinical condition has changed enough so that certain choices that had once been permissible become impermissible. In this "Ethics Rounds," we present a case of triplets born at the borderline of viability. We sought comments from the triplets' parents, the doctors and ethicist who were caring for the infants, and a bioethicist/neonatologist from another hospital.

  10. Tough Decisions for Premature Triplets.

    Science.gov (United States)

    Hurst, Ashley; Vergales, Brooke D; Paget-Brown, Alix; Mercurio, Mark; Lantos, John D

    2016-02-01

    When infants are born at the borderline of viability, doctors and parents have to make tough decisions about whether to institute intensive care or provide only palliative care. Often, these decisions are made in moments of profound emotional turmoil, and parents receive different information from different health professionals. Communication can become garbled. It may be difficult to tell when and whether the patient's clinical condition has changed enough so that certain choices that had once been permissible become impermissible. In this "Ethics Rounds," we present a case of triplets born at the borderline of viability. We sought comments from the triplets' parents, the doctors and ethicist who were caring for the infants, and a bioethicist/neonatologist from another hospital. PMID:26738882

  11. Higher triplet state of fullerene C{sub 70} revealed by electron spin relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Uvarov, Mikhail N., E-mail: uvarov@kinetics.nsc.ru [Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Institutskaya St. 3, 630090 Novosibirsk (Russian Federation); Behrends, Jan [Berlin Joint EPR Lab, Freie Universität Berlin, Arnimallee 14, 14195 Berlin (Germany); Kulik, Leonid V. [Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Institutskaya St. 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova St. 2, Novosibirsk (Russian Federation)

    2015-12-28

    Spin-lattice relaxation times T{sub 1} of photoexcited triplets {sup 3}C{sub 70} in glassy decalin were obtained from electron spin echo inversion recovery dependences. In the range 30–100 K, the temperature dependence of T{sub 1} was fitted by the Arrhenius law with an activation energy of 172 cm{sup −1}. This indicates that the dominant relaxation process of {sup 3}C{sub 70} is described by an Orbach-Aminov mechanism involving the higher triplet state t{sub 2} which lies 172 cm{sup −1} above the lowest triplet state t{sub 1}. Chemical modification of C{sub 70} fullerene not only decreases the intrinsic triplet lifetime by about ten times but also increases T{sub 1} by several orders of magnitude. The reason for this is the presence of a low-lying excited triplet state in {sup 3}C{sub 70} and its absence in triplet C{sub 70} derivatives. The presence of the higher triplet state in C{sub 70} is in good agreement with the previous results from phosphorescence spectroscopy.

  12. Magnetic Field Effects on Triplet-Triplet Annihilation in Solutions: Modulation of Visible/NIR Luminescence

    OpenAIRE

    Mani, Tomoyasu; Vinogradov, Sergei A.

    2013-01-01

    Photon upconversion based on sensitized triplet-triplet annihilation (TTA) presents interest for such areas as photovoltaics and imaging. Usually energy upconversion is observed as p-type delayed fluorescence from molecules whose triplet states are populated via energy transfer from a suitable triplet donor, followed by TTA. Magnetic field effects (MFE) on delayed fluorescence in molecular crystals are well known; however, there exist only a few examples of MFE on TTA in solutions, and all of...

  13. Design and construction of triplet atmospheric cold plasma jet for sterilization

    Directory of Open Access Journals (Sweden)

    F. Sohbatzadeh

    2014-03-01

    Full Text Available In this paper, construction of triplet atmospheric plasma jet using argon, air, oxygen and nitrogen gases is reported. Bactericidal effect of the plasma jet is also investigated. To that end, longitudinal geometric configuration for the electrodes was chosen because it would increase the jet length. Electrical characteristics, jet length dependencies on the applied voltage and gas flow rate were decided, experimentally. Relative concentrations of chemical reactive species such as ozone, atomic oxygen, NOx compounds and hydroxyl were measured using optical emission spectroscopy. It was seen that atomic oxygen and ozone concentrations with triplet plasma jet are more than the concentration of single plasma jet. Triplet plasma jet was also used for sterilization of solid and liquid surfaces to disinfect gram-negative and gram-positive Escherichia coli and Streptococcus pyogenes bacteria. The results verified the effectiveness of the triplet plasma jet for killing bacteria.

  14. Charge pumping due to triplet vector chirality in ferromagnet/triplet superconductor junctions

    OpenAIRE

    Yokoyama, Takehito

    2011-01-01

    We investigate charge pumping in ferromagnet/triplet superconductor junctions where the magnetization of the ferromagnet is inhomogeneous and dynamical. It is shown that charge current is pumped due to the coupling of the localized spin with triplet vector spin chirality, vector spin chirality formed by the triplet vector of Cooper pairing. Physical mechanism of the charge pumping is also discussed.

  15. Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1968-01-01

    This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.

  16. The near elimination of triplets in IVF.

    Science.gov (United States)

    Gerris, Jan

    2007-01-01

    In Antwerp, single embryo transfers (SET) have increased, and this change in policy has seen the incidence of singletons rise from 70 to 90%, twins drop from 25 to 10%, and triplets drop from 1-2% to none at all. At a national and regional level, changes have been much more dramatic as a result of a change in the law in 2003 mandating SET. Data show a huge increase in the number of treatment cycles and a dramatic rise in SET. Rates of twins and triplets have dropped considerably. European data indicate wide differences in the incidence of triplets between countries, varying between 0% (e.g.Slovenia, Iceland, Lithuania) and 4.4% (Hungary), but almost nothing is known about the true incidence of fetal reduction. US data indicate some decrease in triplets during recent years, but certainly nowhere near elimination. These data suggest that in some countries, IVF triplets have almost been eliminated, but the problem is masked by significant fetal reductions. Where SET is not widely used, triplets are still frequent. A correlation appears to exist between the percentage of SET cycles and the incidence of triplets. It is suggested that the solution to almost totally eliminate triplets after IVF is single embryo transfer.

  17. Distribution of Triplet Separators in Bacterial Genomes

    Institute of Scientific and Technical Information of China (English)

    HU Rui; ZHENG Wei-Mou

    2001-01-01

    Distributions of triplet separator lengths for two bacterial complete genomes are analyzed. The theoretical distributions for the independent random sequence and the first-order Markov chain are derived and compared with the distributions of the bacterial genomes. A prominent double band structure, which does not exist in the theoretical distributions, is observed in the bacterial distributions for most triplets.``

  18. Spectroscopy

    CERN Document Server

    Walker, S

    1976-01-01

    The three volumes of Spectroscopy constitute the one comprehensive text available on the principles, practice and applications of spectroscopy. By giving full accounts of those spectroscopic techniques only recently introduced into student courses - such as Mössbauer spectroscopy and photoelectron spectroscopy - in addition to those techniques long recognised as being essential in chemistry teaching - sucha as e.s.r. and infrared spectroscopy - the book caters for the complete requirements of undergraduate students and at the same time provides a sound introduction to special topics for graduate students.

  19. Diphotons from an Electroweak Triplet-Singlet

    Energy Technology Data Exchange (ETDEWEB)

    Howe, Kiel [Fermilab; Knapen, Simon [UC, Berkeley; Robinson, Dean J. [UC, Berkeley

    2016-03-29

    The neutral component of a real pseudoscalar electroweak (EW) triplet can produce a diphoton excess at 750 GeV, if it is somewhat mixed with an EW singlet pseudoscalar. This triplet-singlet mixing allows for greater freedom in the diboson branching ratios than the singlet-only case, but it is still possible to probe the parameter space extensively with 300 fb$^{-1}$. The charged component of the triplet is pair-produced at the LHC, which results in a striking signal in the form of a pair of $W\\gamma$ resonances with an irreducible rate of 0.27 fb. Other signatures include multiboson final states from cascade decays of the triplet-singlet neutral states. A large class of composite models feature both EW singlet and triplet pseudo-Nambu Goldstone bosons in their spectrum, with the diboson couplings generated by axial anomalies.

  20. Definition and determination of the triplet-triplet energy transfer reaction coordinate

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, Felipe; Marazzi, Marco; Castaño, Obis; Frutos, Luis Manuel, E-mail: luisma.frutos@uah.es [Departamento de Química Física, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Acuña, A. Ulises [Instituto de Química Física “Rocasolano”, C.S.I.C., Serrano 119, 28006 Madrid (Spain)

    2014-01-21

    A definition of the triplet-triplet energy transfer reaction coordinate within the very weak electronic coupling limit is proposed, and a novel theoretical formalism is developed for its quantitative determination in terms of internal coordinates The present formalism permits (i) the separation of donor and acceptor contributions to the reaction coordinate, (ii) the identification of the intrinsic role of donor and acceptor in the triplet energy transfer process, and (iii) the quantification of the effect of every internal coordinate on the transfer process. This formalism is general and can be applied to classical as well as to nonvertical triplet energy transfer processes. The utility of the novel formalism is demonstrated here by its application to the paradigm of nonvertical triplet-triplet energy transfer involving cis-stilbene as acceptor molecule. In this way the effect of each internal molecular coordinate in promoting the transfer rate, from triplet donors in the low and high-energy limit, could be analyzed in detail.

  1. The large- and small-scale CaII K structure of the Milky Way from observations of Galactic and Magellanic sightlines

    CERN Document Server

    Smoker, J V; Fox, A J

    2015-01-01

    Aims: By utilising spectra of early-type stellar probes of known distances in the same region of the sky, the large and small-scale (pc) structure of the Galactic ISM can be investigated. This paper determines the variation in line strength of CaII at 3933.661 A, as a function of probe separation for a sample of stars, including many sightlines in the Magellanic Clouds. Methods: FLAMES-GIRAFFE data taken with the VLT towards early-type stars in 3 Galactic & 4 Magellanic open clusters in CaII are used to obtain the velocity, EW, column density and line width of IS Galactic Ca for a total of 657 stars, of which 443 are Magellanic sightlines. In each cluster there are 43-110 stars observed. Additionally, FEROS and UVES CaII & NaI spectra of 21 Galactic & 154 Magellanic early-type stars are presented and combined with data from the literature to study the Ca column density/parallax relationship. Results: For the four Magellanic clusters studied with FLAMES, the strength of the Galactic IS CaII K EW ov...

  2. Charge Carrier Generation Followed by Triplet State Formation, Annihilation, and Carrier Recreation in PBDTTT-C:PC 60 BM Photovoltaic Blends

    KAUST Repository

    Gehrig, Dominik W.

    2015-05-22

    Triplet state formation after photoexcitation of low-bandgap polymer:fullerene blends has recently been demonstrated, however, the precise mechanism and its impact on solar cell performance is still under debate. Here, we study exciton dissociation, charge carrier generation and triplet state formation in low-bandgap polymer PBDTTT-C:PC60BM bulk heterojunction photovoltaic blends by a combination of fs-µs broadband Vis-NIR transient absorption (TA) pump-probe spectroscopy and multivariate curve resolution (MCR) data analysis. We found sub-ps exciton dissociation and charge generation followed by sub-ns triplet state creation. The carrier dynamics and triplet state dynamics exhibited a very pronounced intensity dependence indicating non-geminate recombination of free carriers is the origin of triplet formation in these blends. Triplets were found to be the dominant state present on the nanosecond timescale. Surprisingly, the carrier population increased again on the ns-µs timescale. We attribute this to triplet-triplet annihilation and the formation of higher energy excited states that subsequently underwent charge transfer. This unique dip and recovery of the charge population is a clear indication that triplets are formed by non-geminate recombination, as such a kinetic is incompatible with a monomolecular triplet state formation process.

  3. Higgs triplets and limits from precision measurements

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mu-Chun; /Fermilab; Dawson, Sally; Krupovnickas, Tadas; /Brookhaven

    2006-04-01

    In this letter, they present the results on a global fit to precision electroweak data in a Higgs triplet model. In models with a triplet Higgs boson, a consistent renormalization scheme differs from that of the Standard Model and the global fit shows that a light Higgs boson with mass of 100-200 GeV is preferred. Triplet Higgs bosons arise in many extensions of the Standard Model, including the left-right model and the Little Higgs models. The result demonstrates the importance of the scalar loops when there is a large mass splitting between the heavy scalars. It also indicates the significance of the global fit.

  4. Cooper pairs spintronics in triplet spin valves.

    Science.gov (United States)

    Romeo, F; Citro, R

    2013-11-27

    We study a spin valve with a triplet superconductor spacer intercalated between two ferromagnets with noncollinear magnetizations. We show that the magnetoresistance of the triplet spin valve depends on the relative orientations of the d vector, characterizing the superconducting order parameter, and the magnetization directions of the ferromagnetic layers. For devices characterized by a long superconductor, the effects of a polarized current sustained by Cooper pairs only are observed. In this regime, a supermagnetoresistance effect emerges, and the chiral symmetry of the order parameter of the superconducting spacer is easily recognized. Our findings open new perspectives in designing spintronics devices based on the cooperation of ferromagnetic and triplet correlations. PMID:24329463

  5. VizieR Online Data Catalog: CaII spectroscopy of SMC red giants. IV. (Parisi+, 2016)

    Science.gov (United States)

    Parisi, M. C.; Geisler, D.; Carraro, G.; Claria, J. J.; Villanova, S.; Gramajo, L. V.; Sarajedini, A.; Grocholski, A. J.

    2016-09-01

    This paper is a continuation of our previous work wherein we determined and analyzed the metallicity of 29 Small Magellanic Cloud (SMC) clusters (Parisi et al. 2009, Cat. J/AJ/138/517; Parisi et al. 2015, Cat. J/AJ/149/154) and that of a sample of ~350 red giant field stars (Parisi et al. 2010, Cat. J/AJ/139/1168) surrounding the 15 SMC star clusters studied in Parisi et al. 2009 (Cat. J/AJ/138/517). Here we add the ~400 red giants in 15 fields that surround the 14 star clusters studied in Parisi et al. 2015 (Cat. J/AJ/149/154) (in Parisi et al. 2015, Cat. J/AJ/149/154, we discard the cluster B113, but we can still use the surrounding field stars). We repeat here the identical procedures followed in Parisi et al. 2010 (Cat. J/AJ/139/1168). We refer the reader to Parisi et al. 2015 (Cat. J/AJ/149/154) for details regarding the selection of the cluster sample, the spectroscopic targets, and the observations. The list of the star clusters studied in Parisi et al. 2015 (Cat. J/AJ/149/154) can be seen in Table1 of that paper. Each cluster was centered on the master chip, while surrounding field stars were observed in both the master and secondary CCD. Pre-images in the V and I bands and the spectra of selected stars were obtained as part of programs 0.82B-0505 and 384.B-0687. The selection of spectroscopic targets was made on the corresponding (V, V-I) CMD by choosing stars located along the red giant branch. The spectroscopic observations were performed in service mode with the instrument FORS2 on the Very Large Telescope (VLT) in mask exchange unit mode (MXU), with the same instrumental setup as in Grocholski et al. 2006 (Cat. J/AJ/132/1630) and Parisi et al. 2009 (Cat. J/AJ/138/517). A very few stars have signal-to-noise ratio (S/N)~15pixel-1, but the remaining targets have S/N between ~20 and ~80pixel-1. Information about exposure times, size of the slits, seeing, and characteristics of the obtained spectra can be found in Section 3 of Parisi et al. 2015 (Cat. J/AJ/149/154). (2 data files).

  6. The molecular photophysics of chlorophyl : a study of its triplet state

    NARCIS (Netherlands)

    Kleibeuker, J.F.

    1977-01-01

    The lowest excited triplet state T 0 of chlorophyll a , chlorophyll b , bacteriochlorophyll and corresponding pheophytins has been studied by magnetic resonance and optical spectroscopy. Zero field splitting (US) parameters D and E, populating rates, a

  7. Magnetic Field Effects on Triplet-Triplet Annihilation in Solutions: Modulation of Visible/NIR Luminescence.

    Science.gov (United States)

    Mani, Tomoyasu; Vinogradov, Sergei A

    2013-08-01

    Photon upconversion based on sensitized triplet-triplet annihilation (TTA) presents interest for such areas as photovoltaics and imaging. Usually energy upconversion is observed as p-type delayed fluorescence from molecules whose triplet states are populated via energy transfer from a suitable triplet donor, followed by TTA. Magnetic field effects (MFE) on delayed fluorescence in molecular crystals are well known; however, there exist only a few examples of MFE on TTA in solutions, and all of them are limited to UV-emitting materials. Here we present MFE on TTA-mediated visible and near infrared (NIR) emission, sensitized by far-red absorbing metalloporphyrins in solutions at room temperature. In addition to visible delayed fluorescence from annihilator, we also observed NIR emission from the sensitizer, occurring as a result of triplet-triplet energy transfer back from annihilator, termed "delayed phosphorescence". This emission also exhibits MFE, but opposite in sign to the annihilator fluorescence.

  8. Helium-like triplet diagnostics

    CERN Document Server

    Dubau, J; Dubau, Jacques; Porquet, Delphine

    2002-01-01

    The 1s2-1s2l lines are the most intense He-like ions lines. They are used as spectroscopic diagnostics for solar active regions as well as for different laboratory plasmas. Nowadays, it exits very high spectral resolution instruments and, for intense X-ray sources, one can do spectroscopic diagnostics from line ratios. With XMM (RGS) and Chandra (LETGS, HETGS) spectral resolutions and for several atomic elements, it is particularly possible to separate a 3 blended line set, the so-called He-like triplet: Resonance (r), Intercombination (i) and Forbidden (f), which are dominated respectively by lines issued from the following levels : 1s2p 1P1, 1s2p 3P1,2 and 1s2s 3S1. We shall show that the measurement of two different ratios between these 3 lines (R = f/i and G = (f + i)/r) give quantitative informations on the nature of the emitting plasma (photo-ionized or collisional) and on its electronic density and temperature. A more refined analysis must also include satellite line contributions.

  9. Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules.......This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules....

  10. Chemically induced dynamic electron polarization investigation of the triplet-radical system in the solution of the triplet quencher

    Institute of Scientific and Technical Information of China (English)

    LU, Tong-Xing; CUI, Zhi-Feng; XU, Xin-Sheng; ZHANG, Xian-Yi

    2000-01-01

    The chemically induced dynamic electron polariztiion (CIDEP) of the triplet molecule/triplet quencher/2,2,6,6-te tranethyl-1-piperidinyioxyl (TEMPO) systems were measured using the high time-resolved FESR spectrometer. The competi tion between the radical-triplet pair mechanism (RTPM) and triplet mechanism (TM) or radical pair mechanism (RPM) polarization in the solution of the triplet quencher was investi gated, and the relationship between reaction rate of the radi cal-triplet pair and quenching rate of triplet was deduced.

  11. Triplet excitons in natural photosynthetic and artificial light harvesting systems: Measurement and modeling

    Science.gov (United States)

    Hartzler, Daniel Allen

    Under full sunlight, unprotected (Bacterio)Chlorophyll ((B)Chl) molecules photodegrade in a matter of minutes. This is the result of the generation of highly reactive singlet oxygen (1O2) by energy transfer from the (B)Chl triplet state (3(B)Chl) to the oxygen ground state. Natural photosynthetic systems must protect themselves from 1O2, typically done by positioning carotenoids within a few angstroms of each (B)Chl molecule to quench 3(B)Chl states. Using phosphorescence spectroscopy and computational modeling, we investigated alternative, carotenoid independent, mechanisms which nature may employ to prevent 1O2 sensitization by lowering the energy of 3(B)Chl below that of 1O2. The two proposed triplet lowering mechanisms investigated were: triplet state lowering by strong pigment-pigment interactions (i.e. triplet exciton formation) and triplet state lowering by pigment-protein interactions. Possible natural examples employing these mechanisms are two structures found in green sulfur bacteria: the chlorosome (an antenna containing ~100000 coupled BChl c, d, or e molecules with unexpectedly high photostability) and the Fenna-Matthews-Olson (FMO) complex (an auxiliary antenna containing eight seemingly unprotected BChl a molecules). Measurements performed on linear aggregates of the dye perylene diimide (PDI) show that triplet exciton formation does reduce the triplet state energy. However, direct measurement of triplet state energies for the chlorosome and FMO complex proved experimentally difficult, thus an alternative approach was used to calculate these energies using empirical and excitonic models. Since the use of excitonic modeling requires knowledge of both the pigment site energies and the pigment-pigment interactions (i.e. couplings), work was performed to catalog the monomeric singlet and triplet state energies of all known natural (B)Chl pigments by direct measurement or computational modeling and to characterize the triplet-triplet (T-T) coupling in

  12. Triplet excited state spectra and dynamics of carotenoids from the thermophilic purple photosynthetic bacterium Thermochromatium tepidum

    Energy Technology Data Exchange (ETDEWEB)

    Niedzwiedzki, Dariusz; Kobayashi, Masayuki; Blankenship, R. E.

    2011-01-13

    Light-harvesting complex 2 from the anoxygenic phototrophic purple bacterium Thermochromatium tepidum was purified and studied by steady-state absorption, fluorescence and flash photolysis spectroscopy. Steady-state absorption and fluorescence measurements show that carotenoids play a negligible role as supportive energy donors and transfer excitation to bacteriochlorophyll-a with low energy transfer efficiency of ~30%. HPLC analysis determined that the dominant carotenoids in the complex are rhodopin and spirilloxanthin. Carotenoid excited triplet state formation upon direct (carotenoid) or indirect (bacteriochlorophyll-a Q{sub x} band) excitation shows that carotenoid triplets are mostly localized on spirilloxanthin. In addition, no triplet excitation transfer between carotenoids was observed. Such specific carotenoid composition and spectroscopic results strongly suggest that this organism optimized carotenoid composition in the light-harvesting complex 2 in order to maximize photoprotective capabilities of carotenoids but subsequently drastically suppressed their supporting role in light-harvesting process.

  13. Carborane-Based Carbonic Anhydrase Inhibitors: Insight into CAII/CAIX Specificity from a High-Resolution Crystal Structure, Modeling, and Quantum Chemical Calculations

    Directory of Open Access Journals (Sweden)

    Pavel Mader

    2014-01-01

    Full Text Available Carborane-based compounds are promising lead structures for development of inhibitors of carbonic anhydrases (CAs. Here, we report structural and computational analysis applicable to structure-based design of carborane compounds with selectivity toward the cancer-specific CAIX isoenzyme. We determined the crystal structure of CAII in complex with 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane at 1.0 Å resolution and used this structure to model the 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane interactions with CAIX. A virtual glycine scan revealed the contributions of individual residues to the energy of binding of 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane to CAII and CAIX, respectively.

  14. Carborane-Based Carbonic Anhydrase Inhibitors: Insight into CAII/CAIX Specificity from a High-Resolution Crystal Structure, Modeling, and Quantum Chemical Calculations

    Science.gov (United States)

    Mader, Pavel; Pecina, Adam; Cígler, Petr; Lepšík, Martin; Šícha, Václav; Hobza, Pavel; Grüner, Bohumír; Fanfrlík, Jindřich; Brynda, Jiří; Řezáčová, Pavlína

    2014-01-01

    Carborane-based compounds are promising lead structures for development of inhibitors of carbonic anhydrases (CAs). Here, we report structural and computational analysis applicable to structure-based design of carborane compounds with selectivity toward the cancer-specific CAIX isoenzyme. We determined the crystal structure of CAII in complex with 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane at 1.0 Å resolution and used this structure to model the 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane interactions with CAIX. A virtual glycine scan revealed the contributions of individual residues to the energy of binding of 1-methylenesulfamide-1,2-dicarba-closo-dodecaborane to CAII and CAIX, respectively. PMID:25309911

  15. Colored triplets with integral quantum numbers

    International Nuclear Information System (INIS)

    The systematics of low-lying hadron spectra and the relations between mass, cross-section and magnetic moment in terms of ''constituent'' quarks on one hand, and abstraction of the properties of hadronic weak and electromagnetic current in terms of ''current'' quarks on the other hand have been extremely useful. In the category of three triplet models, there are several versions with the varying degree of similarity and difference among them. These include; (1) the paraquarks of order three, (2) the three triplets with SU(3)' x SU(3)'' symmetry, (3) SUB version by Cabibbo et al., and (4) perfect ''color'' symmetry by Gell-Mann. The physical difference among these various versions of the three triplet models and their consequence are discussed with respect to some of the current theoretical and experimental topics. (Iwase, T.)

  16. Triplet correlation functions in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Dhabal, Debdas; Chakravarty, Charusita, E-mail: charus@chemistry.iitd.ac.in [Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016 (India); Singh, Murari [School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Wikfeldt, Kjartan Thor [Science Institute, University of Iceland, 107 Reykjavik (Iceland)

    2014-11-07

    Triplet correlations have been shown to play a crucial role in the transformation of simple liquids to anomalous tetrahedral fluids [M. Singh, D. Dhabal, A. H. Nguyen, V. Molinero, and C. Chakravarty, Phys. Rev. Lett. 112, 147801 (2014)]. Here we examine triplet correlation functions for water, arguably the most important tetrahedral liquid, under ambient conditions, using configurational ensembles derived from molecular dynamics (MD) simulations and reverse Monte Carlo (RMC) datasets fitted to experimental scattering data. Four different RMC data sets with widely varying hydrogen-bond topologies fitted to neutron and x-ray scattering data are considered [K. T. Wikfeldt, M. Leetmaa, M. P. Ljungberg, A. Nilsson, and L. G. M. Pettersson, J. Phys. Chem. B 113, 6246 (2009)]. Molecular dynamics simulations are performed for two rigid-body effective pair potentials (SPC/E and TIP4P/2005) and the monatomic water (mW) model. Triplet correlation functions are compared with other structural measures for tetrahedrality, such as the O–O–O angular distribution function and the local tetrahedral order distributions. In contrast to the pair correlation functions, which are identical for all the RMC ensembles, the O–O–O triplet correlation function can discriminate between ensembles with different degrees of tetrahedral network formation with the maximally symmetric, tetrahedral SYM dataset displaying distinct signatures of tetrahedrality similar to those obtained from atomistic simulations of the SPC/E model. Triplet correlations from the RMC datasets conform closely to the Kirkwood superposition approximation, while those from MD simulations show deviations within the first two neighbour shells. The possibilities for experimental estimation of triplet correlations of water and other tetrahedral liquids are discussed.

  17. Definition and determination of the triplet-triplet energy transfer reaction coordinate.

    Science.gov (United States)

    Zapata, Felipe; Marazzi, Marco; Castaño, Obis; Acuña, A Ulises; Frutos, Luis Manuel

    2014-01-21

    A definition of the triplet-triplet energy transfer reaction coordinate within the very weak electronic coupling limit is proposed, and a novel theoretical formalism is developed for its quantitative determination in terms of internal coordinates The present formalism permits (i) the separation of donor and acceptor contributions to the reaction coordinate, (ii) the identification of the intrinsic role of donor and acceptor in the triplet energy transfer process, and (iii) the quantification of the effect of every internal coordinate on the transfer process. This formalism is general and can be applied to classical as well as to nonvertical triplet energy transfer processes. The utility of the novel formalism is demonstrated here by its application to the paradigm of nonvertical triplet-triplet energy transfer involving cis-stilbene as acceptor molecule. In this way the effect of each internal molecular coordinate in promoting the transfer rate, from triplet donors in the low and high-energy limit, could be analyzed in detail. PMID:25669358

  18. Spontaneous Triplets Carried in a Uterus Didelphys

    OpenAIRE

    Jessica R. Jackson; Brittney Williams; James Thorp

    2014-01-01

    Background: Spontaneous triplets in a uterus didelphys are an extremely rare finding. Only four other cases are reported in the literature. Case: A 24 year old gravida 3 para 2-0-0-2 conceived spontaneous triplets in a uterine didelphys. She developed cervical insufficiency and underwent cerclage placement at 17 weeks. After spontaneous rupture of membranes at 29 weeks gestation, she underwent repeat cesarean section, with delivery of three viable fetuses. Mother and all three babies are c...

  19. Ultrabright fluorescent OLEDS using triplet sinks

    Science.gov (United States)

    Zhang, Yifan; Forrest, Stephen R; Thompson, Mark

    2013-06-04

    A first device is provided. The first device further comprises an organic light emitting device. The organic light emitting device further comprises an anode, a cathode, and an emissive layer disposed between the anode and the cathode. The emissive layer further comprises an organic host compound, an organic emitting compound capable of fluorescent emission at room temperature, and an organic dopant compound. The triplet energy of the dopant compound is lower than the triplet energy of the host compound. The dopant compound does not strongly absorb the fluorescent emission of the emitting compound.

  20. Relationship between breakthrough curve and adsorption isotherm of Ca(II) imprinted chitosan microspheres for metal adsorption

    Institute of Scientific and Technical Information of China (English)

    Yangcheng Lu; Jing He; Longwen Wu; Guangsheng Luo

    2016-01-01

    In this work, an equilibrium-dispersion model was successfully established to describe the breakthrough performance of Ca(II) imprinted chitosan (Ca(II)-CS) microspheres packed column for metal adsorption, and the assumptions of Langmuir isotherms and axial dispersion controlled mass transfer process were confirmed. The axial dispersion coefficient in Ca(II)-CS microspheres packed column was found to be almost proportional to the linear velocity and fit for prediction through single breakthrough test. Sensitivity analysis for breakthrough curve indicated the axial dispersion coefficient as well as Langmuir coefficient was sensitive variable for deep removal requirement. The retrieval of the adsorption isotherms of Ca(II)-CS microspheres from breakthrough curve was fulfilled by model ing calibration. A strategy based on the correlation between adsorption isotherms and breakthrough performance was further proposed to simplify the column adsorption design using absorbents with smal/uniform size and fast adsorption kinetics like Ca(II)-CS microspheres to cut down the gap between lab and industry.

  1. Ultrafast electronic and vibrational dynamics in brominated aluminum corroles: Energy relaxation and triplet formation

    Directory of Open Access Journals (Sweden)

    T. Stensitzki

    2016-07-01

    Full Text Available We combined femtosecond (fs VIS pump–IR probe spectroscopy with fs VIS pump–supercontinuum probe spectroscopy to characterize the photoreaction of the hexacoordinated Al(tpfc-Br8(py2 in a comprehensive way. Upon fs excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a time constant of (250 ± 80 fs to the S2 and S1 electronic excited states. This is evident from the rise time of the stimulated emission signal in the visible spectral range. On the same time scale, narrowing of broad infrared signals in the C=C stretching region around 1500 cm−1 is observed. Energy redistribution processes are visible in the vibrational and electronic dynamics with time constants between ∼2 ps and ∼20 ps. Triplet formation is detected with a time constant of (95 ± 3 ps. This is tracked by the complete loss of stimulated emission. Electronic transition of the emerging triplet absorption band overlaps considerably with the singlet excited state absorption. In contrast, two well separated vibrational marker bands for triplet formation were identified at 1477 cm−1 and at 1508 cm−1. These marker bands allow a precise identification of triplet dynamics in corrole systems.

  2. Ultrafast electronic and vibrational dynamics in brominated aluminum corroles: Energy relaxation and triplet formation.

    Science.gov (United States)

    Stensitzki, T; Yang, Y; Berg, A; Mahammed, A; Gross, Z; Heyne, K

    2016-07-01

    We combined femtosecond (fs) VIS pump-IR probe spectroscopy with fs VIS pump-supercontinuum probe spectroscopy to characterize the photoreaction of the hexacoordinated Al(tpfc-Br8)(py)2 in a comprehensive way. Upon fs excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a time constant of (250 ± 80) fs to the S2 and S1 electronic excited states. This is evident from the rise time of the stimulated emission signal in the visible spectral range. On the same time scale, narrowing of broad infrared signals in the C=C stretching region around 1500 cm(-1) is observed. Energy redistribution processes are visible in the vibrational and electronic dynamics with time constants between ∼2 ps and ∼20 ps. Triplet formation is detected with a time constant of (95 ± 3) ps. This is tracked by the complete loss of stimulated emission. Electronic transition of the emerging triplet absorption band overlaps considerably with the singlet excited state absorption. In contrast, two well separated vibrational marker bands for triplet formation were identified at 1477 cm(-1) and at 1508 cm(-1). These marker bands allow a precise identification of triplet dynamics in corrole systems. PMID:27226980

  3. Doublet-Triplet Splitting and Fat Branes

    CERN Document Server

    Maru, N

    2001-01-01

    We consider the doublet-triplet splitting problem in supersymmetric SU(5) grand unified theory in five dimensions where the fifth dimension is non-compact. We point out that an unnatural fine-tuning of parameters in order to obtain the light Higgs doublets is not required due to the exponential suppression of the overlap of the wave functions.

  4. Improving Fingerprint Verification Using Minutiae Triplets

    Directory of Open Access Journals (Sweden)

    Leopoldo Altamirano-Robles

    2012-03-01

    Full Text Available Improving fingerprint matching algorithms is an active and important research area in fingerprint recognition. Algorithms based on minutia triplets, an important matcher family, present some drawbacks that impact their accuracy, such as dependency to the order of minutiae in the feature, insensitivity to the reflection of minutiae triplets, and insensitivity to the directions of the minutiae relative to the sides of the triangle. To alleviate these drawbacks, we introduce in this paper a novel fingerprint matching algorithm, named M3gl. This algorithm contains three components: a new feature representation containing clockwise-arranged minutiae without a central minutia, a new similarity measure that shifts the triplets to find the best minutiae correspondence, and a global matching procedure that selects the alignment by maximizing the amount of global matching minutiae. To make M3gl faster, it includes some optimizations to discard non-matching minutia triplets without comparing the whole representation. In comparison with six verification algorithms, M3gl achieves the highest accuracy in the lowest matching time, using FVC2002 and FVC2004 databases.

  5. Birth weight in a large series of triplets

    OpenAIRE

    van Beijsterveldt Catharina EM; Middeldorp Christel M; Lamb Diane J; Vink Jacqueline M; Haak Monique C; Boomsma Dorret I

    2011-01-01

    Abstract Background Triplets are often born premature and with a low birth weight. Because the incidence of triplet births is rare, there are relatively few studies describing triplet birth weight characteristics. Earlier studies are often characterized by small sample sizes and lack information on important background variables such as zygosity. The objective of this study is to examine factors associated with birth weight in a large, population-based sample of triplets registered with the N...

  6. Birth weight in a large series of triplets

    NARCIS (Netherlands)

    D.J. Lamb; C.M. Middeldorp; C.E.M. van Beijsterveldt; J.M. Vink; M.C. Haak; D.I. Boomsma

    2011-01-01

    Background: Triplets are often born premature and with a low birth weight. Because the incidence of triplet births is rare, there are relatively few studies describing triplet birth weight characteristics. Earlier studies are often characterized by small sample sizes and lack information on importan

  7. Long-Lived Triplet Excited States of Bent-Shaped Pentacene Dimers by Intramolecular Singlet Fission.

    Science.gov (United States)

    Sakuma, Takao; Sakai, Hayato; Araki, Yasuyuki; Mori, Tadashi; Wada, Takehiko; Tkachenko, Nikolai V; Hasobe, Taku

    2016-03-24

    Intramolecular singlet fission (ISF) is a promising photophysical process to construct more efficient light energy conversion systems as one excited singlet state converts into two excited triplet states. Herein we synthesized and evaluated bent-shaped pentacene dimers as a prototype of ISF to reveal intrinsic characters of triplet states (e.g., lifetimes of triplet excited states). In this study, meta-phenylene-bridged TIPS-pentacene dimer (PcD-3Ph) and 2,2'-bipheynyl bridged TIPS-pentacene dimer (PcD-Biph) were newly synthesized as bent-shaped dimers. In the steady-state spectroscopy, absorption and emission bands of these dimers were fully characterized, suggesting the appropriate degree of electronic coupling between pentacene moieties in these dimers. In addition, the electrochemical measurements were also performed to check the electronic interaction between two pentacene moieties. Whereas the successive two oxidation peaks owing to the delocalization were observed in a directly linked-pentacene dimer (PcD) by a single bond, the cyclic voltammograms in PcD-Biph and PcD-3Ph implied the weaker interaction compared to that of p-phenylene-bridged TIPS-pentacene dimer (PcD-4Ph) and PcD. The femtosecond and nanosecond transient absorption spectra clearly revealed the slower ISF process in bent-shaped pentacene dimers (PcD-Biph and PcD-3Ph), more notably, the slower relaxation of the excited triplet states in PcD-Biph and PcD-3Ph. Namely, the quantum yields of triplet states (ΦT) by ISF approximately remain constant (ca. 180-200%) in all dimer systems, whereas the lifetimes of the triplet excited states became much longer (up to 360 ns) in PcD-Biph as compared to PcD-4Ph (15 ns). Additionally, the lifetimes of the corresponding triplet states in PcD-Biph and PcD-3Ph were sufficiently affected by solvent viscosity. In particular, the lifetimes of PcD-Biph triplet state in THF/paraffin (1.0 μs) increased up to approximately three times as compared to that in THF

  8. Synthesis and Exciton Dynamics of Triplet Sensitized Conjugated Polymers

    KAUST Repository

    Andernach, Rolf

    2015-07-22

    We report the synthesis of a novel polythiophene-based host-guest copolymer incorporating a Pt-porphyrin complex (TTP-Pt) into the backbone for efficient singlet to triplet polymer exciton sensitization. We elucidated the exciton dynamics in thin films of the material by means of Transient Absorption Spectrosopcy (TAS) on multiple timescales and investigated the mechanism of triplet exciton formation. During sensitization, single exciton diffusion is followed by exciton transfer from the polymer backbone to the complex where it undergoes intersystem crossing to the triplet state of the complex. We directly monitored the triplet exciton back transfer from the Pt-porphyrin to the polymer and find that 60% of the complex triplet excitons are transferred with a time constant of 1087 ps. We propose an equilibrium between polymer and porphyrin triplet states as a result of the low triplet diffusion length in the polymer backbone and hence an increased local triplet population resulting in increased triplet-triplet annihilation. This novel system has significant implications for the design of novel materials for triplet sensitized solar cells and up-conversion layers.

  9. Triplet Higgs boson at hadron colliders

    International Nuclear Information System (INIS)

    The novel feature of a Higgs-triplet representation is a nonzero tree-level coupling of H+W-Z, which is absent in all Higgs-doublet models. We study the associated production of a singly-charged Higgs boson of the Higgs-triplet representation with a W or Z boson at hadron colliders, followed by the H+→W+Z decay. We find that the 2l+4j final state gives an interesting level of signal with a negligible background, plus it allows a full mass reconstruction of the charged-Higgs boson. The cover range of the charged-Higgs mass is between 110 and 200 GeV. (author)

  10. Fermiophobia in a Higgs Triplet Model

    CERN Document Server

    Akeroyd, A G; Rivera, Maximiliano A; Romero, Diego

    2010-01-01

    A Fermiophobic Higgs boson can arise in models with an extended Higgs sector, such as models with scalars in an isospin triplet representation. In a specific model with a scalar triplet and spontaneous violation of lepton number induced by a scalar singlet field, we show that fermiophobia is not a fine-tuned situation, unlike in Two Higgs Doublet Models. We study distinctive signals of fermiophobia which can be probed at the LHC. For the case of a small Higgs mass a characteristic signal would be a moderate B(H ->\\gamma\\gamma) accompanied by a large B(H -> JJ) (where J is a Majoron), the latter being an invisible decay. For the case of a large Higgs mass there is the possibility of dominant H -> ZZ, WW and suppressed H -> JJ decay modes. In this situation, B(H -> ZZ) is larger than B(H -> WW), which differs from the SM prediction.

  11. Nonextensive triplet in geological faults system

    CERN Document Server

    de Freitas, D B; Scheerer, T M; Vilar, C S; Silva, R

    2013-01-01

    The San Andreas fault (SAF) in the USA is one of the most investigated self-organizing systems in nature. In this paper, we studied some geophysical properties of the SAF system in order to analyze the behavior of earthquakes in the context of Tsallis's $q$--Triplet. To that end, we considered 134,573 earthquake events in magnitude interval $2\\leq m<8$, taken from the Southern Earthquake Data Center (SCEDC, 1932 - 2012). The values obtained ("$q$--Triplet"$\\equiv$$\\{$$q$$_{stat}$,$q$$_{sen}$,$q$$_{rel}$$\\}$) reveal that the $q_{stat}$--Gaussian behavior of the aforementioned data exhibit long-range temporal correlations. Moreover, $q_{sen}$ exhibits quasi-monofractal behavior with a Hurst exponent of 0.87.

  12. Intra-Inter Triplet Object Interaction Mechanism in Triplet-Based Hierarchical Interconnection Network

    Directory of Open Access Journals (Sweden)

    Shahnawaz Talpur

    2013-07-01

    Full Text Available Object oriented languages usually avoid direct message passing, due to its complicated implementation, though that is the promising way to communicate in concurrently inherited objects. With the advancement in the high performance computing system, interaction between parallel application objects onto physical cores becomes one of the significant issues, which is not fully explored yet. In object oriented programming attribute data is included in objects and their state can be changed using the methods. Objects enable massage passing to other objects interacting with each other. Comprehensive problems can be molded by object-oriented methodology, and solves difficult program running object-oriented programs.Cores communicate with each other through communicator and groups in MPI, but in our reference architecture TBHIN (Triplet Based Hierarchical Interconnection Network, the cores are already faction in Triplets. We propose IITOIM Model to improve the performance with efficient intra-inter triplet cores communication mechanism between the objects in TBHIN

  13. Dye-Sensitized Solar Cell with Integrated Triplet-Triplet Annihilation Upconversion System.

    Science.gov (United States)

    Nattestad, Andrew; Cheng, Yuen Yap; MacQueen, Rowan W; Schulze, Tim F; Thompson, Fletcher W; Mozer, Attila J; Fückel, Burkhard; Khoury, Tony; Crossley, Maxwell J; Lips, Klaus; Wallace, Gordon G; Schmidt, Timothy W

    2013-06-20

    Photon upconversion (UC) by triplet-triplet annihilation (TTA-UC) is employed in order to enhance the response of solar cells to sub-bandgap light. Here, we present the first report of an integrated photovoltaic device, combining a dye-sensitized solar cell (DSC) and TTA-UC system. The integrated device displays enhanced current under sub-bandgap illumination, resulting in a figure of merit (FoM) under low concentration (3 suns), which is competitive with the best values recorded to date for nonintegrated systems. Thus, we demonstrate both the compatibility of DSC and TTA-UC and a viable method for device integration.

  14. Synthesis, spectroscopic, thermal and anticancer studies of metal-antibiotic chelations: Ca(II), Fe(III), Pd(II) and Au(III) chloramphenicol complexes

    Science.gov (United States)

    Al-Khodir, Fatima A. I.; Refat, Moamen S.

    2016-09-01

    Four Ca(II), Fe(III), Pd(II) and Au(III) complexes of chloramphenicol drug have been synthesized and well characterized using elemental analyses, (infrared, electronic, and 1H-NMR) spectra, magnetic susceptibility measurement, and thermal analyses. Infrared spectral data show that the chloramphenicol drug coordinated to Ca(II), Pd(II) and Au(III) metal ions through two hydroxyl groups with 1:1 or 1:2 M ratios, but Fe(III) ions chelated towards chloramphenicol drug via the oxygen and nitrogen atoms of amide group with 1:2 ratio based on presence of keto↔enol form. The X-ray powder diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) techniques were used to identify the nano-size particles of both iron(III) and gold(III) chloramphenicol complexes. The antimicrobial assessments of the chloramphenicol complexes were scanned and collected the results against of some kind of bacteria and fungi. The cytotoxic activity of the gold(III) complex was tested against the human colon carcinoma (HCT-116) and human hepatocellular carcinoma (HepG-2) tumor cell lines.

  15. Half-metallic superconducting triplet spin valve

    Science.gov (United States)

    Halterman, Klaus; Alidoust, Mohammad

    2016-08-01

    We theoretically study a finite-size S F1N F2 spin valve, where a normal metal (N ) insert separates a thin standard ferromagnet (F1) and a thick half-metallic ferromagnet (F2). For sufficiently thin superconductor (S ) widths close to the coherence length ξ0, we find that changes to the relative magnetization orientations in the ferromagnets can result in substantial variations in the transition temperature Tc, consistent with experimental results [Singh et al., Phys. Rev. X 5, 021019 (2015), 10.1103/PhysRevX.5.021019]. Our results demonstrate that, in good agreement with the experiment, the variations are largest in the case where F2 is in a half-metallic phase and thus supports only one spin direction. To pinpoint the origins of this strong spin-valve effect, both the equal-spin f1 and opposite-spin f0 triplet correlations are calculated using a self-consistent microscopic technique. We find that when the magnetization in F1 is tilted slightly out of plane, the f1 component can be the dominant triplet component in the superconductor. The coupling between the two ferromagnets is discussed in terms of the underlying spin currents present in the system. We go further and show that the zero-energy peaks of the local density of states probed on the S side of the valve can be another signature of the presence of superconducting triplet correlations. Our findings reveal that for sufficiently thin S layers, the zero-energy peak at the S side can be larger than its counterpart in the F2 side.

  16. Singlet-triplet annihilation limits exciton yield in poly(3-hexylthiophene)

    CERN Document Server

    Steiner, Florian; Lupton, John M

    2014-01-01

    Control of chain length and morphology in combination with single-molecule spectroscopy techniques provide a comprehensive photophysical picture of excited-state losses in the prototypical conjugated polymer poly(3-hexylthiophene) (P3HT). A universal self-quenching mechanism is revealed, based on singlet-triplet exciton annihilation, which accounts for the dramatic loss in fluorescence quantum yield of a single P3HT chain between its solution (unfolded) and bulk-like (folded) state. Triplet excitons fundamentally limit the fluorescence of organic photovoltaic materials, which impacts on the conversion of singlet excitons to separated charge carriers, decreasing the efficiency of energy harvesting at high excitation densities. Interexcitonic interactions are so effective that a single P3HT chain of >100 kDa weight behaves like a two-level system, exhibiting perfect photon-antibunching.

  17. Probing the C₆₀ triplet state coupling to nuclear spins inside and out.

    Science.gov (United States)

    Filidou, Vasileia; Mamone, Salvatore; Simmons, Stephanie; Karlen, Steven D; Anderson, Harry L; Kay, Christopher W M; Bagno, Alessandro; Rastrelli, Federico; Murata, Yasujiro; Komatsu, Koichi; Lei, Xuegong; Li, Yongjun; Turro, Nicholas J; Levitt, Malcolm H; Morton, John J L

    2013-09-13

    The photoexcitation of functionalized fullerenes to their paramagnetic triplet electronic state can be studied by pulsed electron paramagnetic resonance (EPR) spectroscopy, whereas the interactions of this state with the surrounding nuclear spins can be observed by a related technique: electron nuclear double resonance (ENDOR). In this study, we present EPR and ENDOR studies on a functionalized exohedral fullerene system, dimethyl[9-hydro (C60-Ih)[5,6]fulleren-1(9H)-yl]phosphonate (DMHFP), where the triplet electron spin has been used to hyperpolarize, couple and measure two nuclear spins. We go on to discuss the extension of these methods to study a new class of endohedral fullerenes filled with small molecules, such as H₂@C₆₀, and we relate the results to density functional calculations. PMID:23918718

  18. Powering the High-Luminosity Triplets

    CERN Document Server

    Ballarino, A

    2015-01-01

    The powering of the magnets in the LHC High-Luminosity Triplets requires production and transfer of more than 150 kA of DC current. High precision power converters will be adopted, and novel High Temperature Superconducting (HTS) current leads and MgB2 based transfer lines will provide the electrical link between the power converters and the magnets. This chapter gives an overview of the systems conceived in the framework of the LHC High-Luminosity upgrade for feeding the superconducting magnet circuits. The focus is on requirements, challenges and novel developments.

  19. Scalar triplet on a domain wall: an exact solution

    CERN Document Server

    Gani, Vakhid A; Radomskiy, Roman V

    2016-01-01

    We study a model with a real scalar Higgs field and a scalar triplet field that allows existence of a topological defect -- a domain wall. The wall breaks the global $O(3)$ symmetry of the model, which gives rise to non-Abelian orientational degrees of freedom. We found an exact analytic solution that describes a domain wall with a localized configuration of the triplet field on it. This solution enables one to calculate contributions to the action from the orientational and translational degrees of freedom of the triplet field. We also study the linear stability of the domain wall with the triplet field switched off.

  20. Higgs Triplet Model with Classically Conformal Invariance

    CERN Document Server

    Okada, Hiroshi; Yagyu, Kei

    2015-01-01

    We discuss an extension of the minimal Higgs triplet model with a classically conformal invariance and with a gauged $U(1)_{B-L}$ symmetry. In our scenario, tiny masses of neutrinos are generated by a hybrid contribution from the type-I and type-II seesaw mechanisms. The shape of the Higgs potential at low energies is determined by solving one-loop renormalization group equations for all the scalar quartic couplings with a set of initial values of parameters at the Planck scale. We find a successful set of the parameters in which the $U(1)_{B-L}$ symmetry is radiatively broken via the Coleman-Weinberg mechanism at the ${\\cal O}$(10) TeV scale, and the electroweak symmetry breaking is also triggered by the $U(1)_{B-L}$ breaking. Under this configuration, we can predict various low energy observables such as the mass spectrum of extra Higgs bosons, and the mixing angles. Furthermore, using these predicted mass parameters, we obtain upper limits on Yukawa couplings among an isospin triplet Higgs field and lepton...

  1. The superconducting spin valve and triplet superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Garifullin, I.A., E-mail: ilgiz_garifullin@yahoo.com [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Leksin, P.V.; Garif' yanov, N.N.; Kamashev, A.A. [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Fominov, Ya.V. [L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation); Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O.G. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Büchner, B. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoO{sub x}/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers. - Highlights: • We studied a spin switch design F1/F2/S. • We prepared a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). • The full spin switch effect for the superconducting current was realized. • We observed its oscillating behavior as a function of the Fe2-layer thickness. • We obtained direct evidence for the long-range triplet superconductivity.

  2. Heavy Vector Triplets: Bridging Theory and Data

    CERN Document Server

    Pappadopulo, Duccio; Torre, Riccardo; Wulzer, Andrea

    2014-01-01

    We introduce a model-independent strategy to study narrow resonances which we apply to a heavy vector triplet of the Standard Model (SM) group for illustration. The method is based on a simplified phenomenological Lagrangian which reproduces a large class of explicit models. Firstly, this allows us to derive robust model-independent phenomenological features and, conversely, to identify the peculiarities of different explicit realizations. Secondly, limits on cross-section times BR can be converted into bounds on a few relevant parameters in a fully analytic way, allowing for an interpretation in any given explicit model. Based on the available 8 TeV LHC analyses, we derive current limits and interpret them for vector triplets arising in weakly coupled (gauge) and strongly coupled (composite) extensions of the SM. We point out that a model-independent limit setting procedure must be based on purely on-shell quantities, like a cross-section times BR. Finite width effects altering the limits can be considerably...

  3. The neonatal outcome in twin versus triplet and quadruplet pregnancies

    Directory of Open Access Journals (Sweden)

    Fatemeh Nasseri

    2009-02-01

    Full Text Available

    • BACKGROUND: To assess the risk of neonatal mortality and morbidity in twin, triplet and quadruplet pregnancies.
    • METHODS: In a retrospective study, the neonatal outcome of all twin, triplet and quadruplet gestations delivered from October 2001 to September 2006 was reviewed. The neonatal outcome of triples and quadruplets was compared with a matched group of twins for gestational age.
    • RESULTS: During a 5-year period, 511 sets of twin pregnancies, 42 sets of triplet and 5 sets of quadruplet pregnancies were studied. The mean of gestational age for twins, triplets and quadruplets were 33.92 ± 3.5 weeks, 30.92 ± 3.8 weeks and 31.60 ± 2.0 weeks, respectively, (P = 0.0001. Triplets and quadruplets weighed less than twins, (P = 0.0001. Neonatal mortality was 13.5% for twins, 26.8% for triplets and 30% for quadruplets. In vitro fertilization, use of ovulation induction agents, and cesarean delivery in the women with triplet and quadruplet were significantly higher than in those with twin pregnancies, (P = 0.0001. The mean age of mothers with triplets and quadruplets was significantly higher than with twins (P = 0.026. There was not a significant difference in respiratory and non-respiratory short outcomes between triplets, quadruplets and twins when matched for gestational age. Apgar score at 1 and 5 minutes was significantly lower in triplets and quadruplets than twins. There was no influence of birth order on neonatal mortality of triplet pregnancy. Neonatal mortality of triplet births was significantly decreased over the 5 years of the study period.
    • CONCLUSIONS: Triplets and quadruplets have a similar neonatal outcome as twins when matched for gestational age. There is no influence of birth on the neonatal mortality of triplet pregnancy. It appears that outcome is mainly dependent on gestational age.
    • KEYWORDS: Neonatal

    • Regularities of Twin, Triplet and Multiplet Prime Numbers

      OpenAIRE

      Weber, H. J.

      2011-01-01

      Classifications of twin primes are established and then applied to triplets that generalize to all higher multiplets. Mersenne and Fermat twins and triplets are treated in this framework. Regular prime number multiplets are related to quadratic and cubic prime number generating polynomials.

    • Three-Triplet Model with Double SU(3) Symmetry

      Science.gov (United States)

      Han, M. Y.; Nambu, Y.

      1965-01-01

      With a view to avoiding some of the kinematical and dynamical difficulties involved in the single triplet quark model, a model for the low lying baryons and mesons based on three triplets with integral charges is proposed, somewhat similar to the two-triplet model introduced earlier by one of us (Y. N.). It is shown that in a U(3) scheme of triplets with integral charges, one is naturally led to three triplets located symmetrically about the origin of I{sub 3} - Y diagram under the constraint that Nishijima-Gell-Mann relation remains intact. A double SU(3) symmetry scheme is proposed in which the large mass splittings between different representations are ascribed to one of the SU(3), while the other SU(3) is the usual one for the mass splittings within a representation of the first SU(3).

    • Triplet Leptogenesis in Left-Right Symmetric Seesaw Models

      CERN Document Server

      Hallgren, Tomas; Ohlsson, Tommy

      2007-01-01

      We discuss scalar triplet leptogenesis in a specific left-right symmetric seesaw model. We show that the Majorana phases that are present in the model can be effectively used to saturate the existing upper limit on the CP-asymmetry of the triplets. We solve the relevant Boltzmann equations and analyze the viability of triplet leptogenesis. It is known for this kind of scenario that the efficiency of leptogenesis is maximal if there exists a hierarchy between the branching ratios of the triplet decays into leptons and Higgs particles. We show that triplet leptogenesis typically favors branching ratios with not too strong hierarchies, since maximal efficiency can only be obtained at the expense of suppressed CP-asymmetries.

    • Triplet-triplet annihilation photon-upconversion: towards solar energy applications.

      Science.gov (United States)

      Gray, Victor; Dzebo, Damir; Abrahamsson, Maria; Albinsson, Bo; Moth-Poulsen, Kasper

      2014-06-14

      Solar power production and solar energy storage are important research areas for development of technologies that can facilitate a transition to a future society independent of fossil fuel based energy sources. Devices for direct conversion of solar photons suffer from poor efficiencies due to spectrum losses, which are caused by energy mismatch between the optical absorption of the devices and the broadband irradiation provided by the sun. In this context, photon-upconversion technologies are becoming increasingly interesting since they might offer an efficient way of converting low energy solar energy photons into higher energy photons, ideal for solar power production and solar energy storage. This perspective discusses recent progress in triplet-triplet annihilation (TTA) photon-upconversion systems and devices for solar energy applications. Furthermore, challenges with evaluation of the efficiency of TTA-photon-upconversion systems are discussed and a general approach for evaluation and comparison of existing systems is suggested.

    • TRIPLET CIRCULAR HOUGH TRANSFORM FOR CIRCLE DETECTION

      Institute of Scientific and Technical Information of China (English)

      Luo Daisheng; He Xiaohai; Teng Qizhi; Tao Qingchuan

      2002-01-01

      A new method, triplet circular Hough transform, is proposed for circle detection in image processing and pattern recognition. In the method, a curve in an image is first detected.Next, a sequence of three points on the curve are selected, a sequence of parameters (a,b,r)corresponding to the three points are calculated by solving the circle equation of the curve, and two 2-D accumulators A(a,b) and R(a,b) are accumulated with 1 and r, respectively. Then the parameters {(a, b, r)} of the circles fitting the curve are determined from A(a, b) and R(a, b) by searching for the local maximum over A(a,b). Because no computation loops over center (a, b)and/or radius r are needed, the method is faster than the basic and directional gradient methods.It needs also much smaller memory for accumulation.

    • Magnetic chains on a triplet superconductor.

      Science.gov (United States)

      Sacramento, P D

      2015-11-11

      The topological state of a two-dimensional triplet superconductor may be changed by an appropriate addition of magnetic impurities. A ferromagnetic magnetic chain at the surface of a superconductor with spin-orbit coupling may eliminate the edge states of a finite system giving rise to localized zero modes at the edges of the chain. The coexistence/competition between the two types of zero modes is considered. The reduction of the system to an effective 1d system gives partial information on the topological properties but the study of the two sets of zero modes requires a two-dimensional treatment. Increasing the impurity density from a magnetic chain to magnetic islands leads to a finite Chern number. At half-filling small concentrations are enough to induce chiral modes.

    • Triplet to Singleton-A Successful Outcome

      Directory of Open Access Journals (Sweden)

      Priya Varshney

      2014-07-01

      Full Text Available We are presenting a case report of triplet pregnancy in a 25 years old lady, in whom single fetal reduction was done at 10 weeks. At 29 weeks, ultrasonography showed fetal demise of second twin. Conservative management was done, after evaluating the status of second twin. Maternal and fetal monitoring was done with PT INR, Ultrasound Doppler weekly till 33 weeks when an emergency cesarean was done due to preterm labour pains. A healthy baby of 1.8 kg was born along with a macerated IUD of 500 gms. Mother and baby are healthy on follow up till date. Hence conservative management should be followed in single fetus demise in twin pregnancy with proper monitoring.

    • Bright Solid State Source of Photon Triplets

      CERN Document Server

      Khoshnegar, Milad; Predojević, Ana; Dalacu, Dan; Prilmüller, Maximilian; Lapointe, Jean; Wu, Xiaohua; Tamarat, Philippe; Lounis, Brahim; Poole, Philip; Weihs, Gregor; Majedi, Hamed

      2015-01-01

      Producing advanced quantum states of light is a priority in quantum information technologies. While remarkable progress has been made on single photons and photon pairs, multipartite correlated photon states are usually produced in purely optical systems by post-selection or cascading, with extremely low efficiency and exponentially poor scaling. Multipartite states enable improved tests of the foundations of quantum mechanics as well as implementations of complex quantum optical networks and protocols. It would be favorable to directly generate these states using solid state systems, for better scaling, simpler handling, and the promise of reversible transfer of quantum information between stationary and flying qubits. Here we use the ground states of two optically active coupled quantum dots to directly produce photon triplets. The wavefunctions of photogenerated excitons localized in these ground states are correlated via molecular hybridization and Coulomb interactions. The formation of a triexciton leads...

    • Electron, Hole, Singlet, and Triplet Energy Transfer in Photoexcited Porphyrin-Naphthalenediimide Dyads.

      Science.gov (United States)

      Yushchenko, Oleksandr; Hangarge, Rahul V; Mosquera-Vazquez, Sandra; Boshale, Sheshanath V; Vauthey, Eric

      2015-06-18

      The excited-state dynamics of two molecular dyads, consisting of zinc (1) and free-base (2) porphyrin connected via a peptide linker to a core-substituted naphthalenediimide (NDI) have been investigated using optical spectroscopy. These dyads exhibit rich photophysics because of the large number of electronic excited states below 3 eV. In the case of 1 in apolar solvents, excitation energy transfer from the vibrationally hot singlet excited porphyrin to the NDI takes place with a 500 fs time constant. Electronic energy ends up in the NDI-localized triplet state, which decays to the ground state on a microsecond timescale. In polar solvents, ground-state recovery is faster by 5 orders of magnitude because of the occurrence of charge separation followed by recombination. On the other hand, excitation energy transfer in 2 takes place in the opposite direction, namely from the NDI to the porphyrin, which then undergoes intersystem crossing to the triplet state, followed by triplet energy transfer back to the NDI. Therefore, four distinct local electronic excited states are consecutively populated after excitation of the NDI unit of 2, with the energy shuttling between the two ends of the dyad. PMID:25418961

    • ARTICLES: Microwave Assisted Synthesis of a New Triplet Iridium(III) Pyrazine Complex

      Science.gov (United States)

      Wu, Qiu-hua; Wang, Chuan-hong; Song, Xi-ming; Zhang, Guo-lin

      2010-06-01

      A new cyclometalated iridium(III) complex Ir(DPP)3 (DPP = 2,3-diphenylpyrazine) was prepared by reaction of DPP with iridium trichloride hydrate under microwave irradiation. The structure of the complex was confirmed by elemental analysis, 1H NMR, and mass spectroscopy. The UV-Vis absorption and photoluminescent properties of the complex were investigated. The complex shows strong 1MLCT (singlet metal to ligand charge-transfer) and 3MLCT (triplet metal to ligand charge-transfer) absorption at 382 and 504 nm, respectively. The complex also shows strong photoluminescence at 573 nm at room temperature. These results suggest the complex to be a promising phosphorescent material.

    • TRIPLET CIRCULAR HOUGH TRANSFORM FOR CIRCLE DETECTION

      Institute of Scientific and Technical Information of China (English)

      LuoDaisheng; HeXiaohai; 等

      2002-01-01

      A new method,triplet circular Hough transform,is proposed for circle detection in image processing and pattern recognition.In the method,a curve in an image is first detected.Next,a sequence of three points on the curve are selected.a sequence of parameters(a,b,r)corresponding to the three points are calculated by solving the circle equation of the curve,and two 2-D accumulators A(a,b)and R(a,b)are accumulated with 1 and r,respectively,Then the parameters{(a,b,r)}of the circles fitting the curve are determined from A(a,b)and R(a,b) by searching for the local maximum over A(a,b).Because no computation loops over center(a,b) and/or radius r are needed,the method is faster than the basic and directional gradient methods It needs also much smaller memory for accumulation.

    • Triplet Pairing in pure neutron matter

      CERN Document Server

      Srinivas, Sarath

      2016-01-01

      We study the zero temperature BCS gaps for the triplet channel in pure neutron matter using Similarity Renormalization Group (SRG) evolved interactions. We use the dependence of the results on the SRG resolution scale, as a tool to analyze medium and many-body corrections. In particular, we study the effects of including the three-body interactions at leading order, which appear at N2LO in the Chiral EFT, as well as that of the first-order self-energy corrections on the zero temperature gap. In addition we also extract the transition temperature as a function of densities and verify the BCS scaling of the zero temperature gaps to the transition temperature. We observe that the self-energy effects are very crucial in order to reduce the SRG resolution scale dependence of the results, while the three-body effects at the leading order do not change the two-body resolution scale dependence. On the other hand, the results depend strongly on the three-body cut-off, emphasizing the importance of the missing higher-o...

    • Ground state of naphthyl cation: Singlet or triplet?

      Energy Technology Data Exchange (ETDEWEB)

      Dutta, Achintya Kumar; Vaval, Nayana, E-mail: np.vaval@ncl.res.in; Pal, Sourav, E-mail: s.pal@ncl.res.in [Physical Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008 (India); Manohar, Prashant U. [Department of Chemistry, BITS Pilani, Pilani Campus (India)

      2014-03-21

      We present a benchmark theoretical investigation on the electronic structure and singlet-triplet(S-T) gap of 1- and 2-naphthyl cations using the CCSD(T) method. Our calculations reveal that the ground states of both the naphthyl cations are singlet, contrary to the results obtained by DFT/B3LYP calculations reported in previous theoretical studies. However, the triplet states obtained in the two structural isomers of naphthyl cation are completely different. The triplet state in 1-naphthyl cation is (π,σ) type, whereas in 2-naphthyl cation it is (σ,σ{sup ′}) type. The S-T gaps in naphthyl cations and the relative stability ordering of the singlet and the triplet states are highly sensitive to the basis-set quality as well as level of correlation, and demand for inclusion of perturbative triples in the coupled-cluster ansatz.

    • Scalar triplet on a domain wall: an exact solution

      Science.gov (United States)

      Gani, Vakhid A.; Lizunova, Mariya A.; Radomskiy, Roman V.

      2016-04-01

      We study a model with a real scalar Higgs field and a scalar triplet field that allows existence of a topological defect — a domain wall. The wall breaks the global O(3) symmetry of the model, which gives rise to non-Abelian orientational degrees of freedom. We found an exact analytic solution that describes a domain wall with a localized configuration of the triplet field on it. This solution enables one to calculate contributions to the action from the orientational and translational degrees of freedom of the triplet field. We also study the linear stability of the domain wall with the triplet field switched off. We obtain that degrees of freedom localized on the wall can appear or do not appear depending on the parameters of the model.

    • Higher-Spin Triplet Fields and String Theory

      Directory of Open Access Journals (Sweden)

      D. Sorokin

      2010-01-01

      Full Text Available We review basic properties of reducible higher-spin multiplets, called triplets, and demonstrate how they naturally appear as part of the spectrum of String Field Theory in the tensionless limit. We show how in the frame-like formulation the triplet fields are endowed with the geometrical meaning of being components of higher-spin vielbeins and connections and present actions describing their free dynamics.

    • Triplet repeat length bias and variation in the human transcriptome

      OpenAIRE

      Molla, Michael; Delcher, Arthur; Sunyaev, Shamil; Cantor, Charles; Kasif, Simon

      2009-01-01

      Length variation in short tandem repeats (STRs) is an important family of DNA polymorphisms with numerous applications in genetics, medicine, forensics, and evolutionary analysis. Several major diseases have been associated with length variation of trinucleotide (triplet) repeats including Huntington's disease, hereditary ataxias and spinobulbar muscular atrophy. Using the reference human genome, we have catalogued all triplet repeats in genic regions. This data revealed a bias in noncoding D...

    • Formylmethylene: the triplet ground state and the lowest singlet state

      OpenAIRE

      Guan, Jun; Randall, Katherine R.; Li, Huidong; Schaefer, Henry F. III

      2013-01-01

      The ground triplet state and lowest singlet state of formylmethylene have been proposed as important intermediates in the Wolff rearrangement of α-diazo ketones into ketenes. The ground triplet state of formylmethylene has been examined experimentally, but the lowest singlet state has yet to be observed. We predict equilibrium geometries, energies, bonding, dipole moments, and harmonic vibrational frequencies for these two lowest states of formylmethylene at the cc-pVQZ CCSD...

  1. Exploring Hyperchargeless Higgs Triplet Model up to the Planck Scale

    CERN Document Server

    Khan, Najimuddin

    2016-01-01

    We examine extended Higgs triplet of Standard Model taking into consideration the Higgs-like particle discovery at the LHC with mass around 125 GeV. We evaluate the bounds on the scalar potential through the unitarity of the scattering-matrix. Considering with and without $Z_2$-symmetry on the extra triplet, we derive constraints on the parameter space. We identify the region of the parameter space that corresponds to the stability and metastability of the electroweak vacuum.

  2. Controlling a Singlet-Triplet Spin Qubit

    Science.gov (United States)

    Petta, Jason

    2006-03-01

    An attractive candidate for a solid-state quantum bit is based on semiconductor quantum dots, which allow controlled coupling of one or more electrons, using rapidly switchable voltages applied to electrostatic gates [1]. Due to tight confinement and the high degree of isolation from the environment, spin relaxation times in quantum dots can approach millisecond timescales [2]. In this talk I will describe how fast electrical control of the exchange interaction can be used to coherently manipulate two-electron spin states [3]. By separating a spin singlet state on-chip, we measure an ensemble averaged spin dephasing time T2^* of 10 ns, limited by the contact hyperfine interaction with the GaAs host nuclei. We develop quantum control techniques based on the exchange interaction to correct for hyperfine dephasing. Coherent spin state rotations are achieved, including spin SWAP. By using a spin-echo pulse sequence based on the exchange interaction we extend the spin coherence time, T2 beyond 1.2 microseconds. The quantum control techniques demonstrated here are general and may be used to manipulate singlet-triplet spin qubits in carbon nanotubes, electrons on helium, and semiconducting nanowires. In collaboration with A. C. Johnson, J. M. Taylor, E. A. Laird, A. Yacoby, M. D. Lukin, C. M. Marcus, M. P. Hanson, A. C. Gossard. [1] J. R. Petta, A. C. Johnson, A. Yacoby, C. M. Marcus, A. C. Gossard, M. P. Hanson, Phys. Rev. B 72, R161301 (2005). [2] A. C. Johnson, J. R. Petta, J. M. Taylor, A. Yacoby, M. D. Lukin, C. M. Marcus, M. P. Hanson, A. C. Gossard, Nature 435, 925 (2005). [3] J. R. Petta, A. C. Johnson, J. M. Taylor, E. A. Laird, A. Yacoby, M. D. Lukin, C. M. Marcus, M. P. Hanson, A. C. Gossard, Science 309, 2180 (2005).

  3. Line absorption of He-like triplet lines by Li-like ions. Caveats of using line ratios of triplets for plasma diagnostics

    OpenAIRE

    Mehdipour, M.; Kaastra, J. S.; Raassen, A. J. J.

    2015-01-01

    He-like ions produce distinctive series of triplet lines under various astrophysical conditions. However, this emission can be affected by line absorption from Li-like ions in the same medium. We investigate this absorption of He-like triplets and present the implications for diagnostics of plasmas in photoionisation equilibrium using the line ratios of the triplets. Our computations were carried out for the O VI and Fe XXIV absorption of the O VII and Fe XXV triplet emission lines, respectiv...

  4. Broadband visible light-harvesting naphthalenediimide (NDI) triad: study of the intra-/intermolecular energy/electron transfer and the triplet excited state.

    Science.gov (United States)

    Wu, Shuang; Zhong, Fangfang; Zhao, Jianzhang; Guo, Song; Yang, Wenbo; Fyles, Tom

    2015-05-21

    A triad based on naphthalenediimides (NDI) was prepared to study the intersystem crossing (ISC), the fluorescence-resonance-energy-transfer (FRET), as well as the photoinduced electron transfer (PET) processes. In the triad, the 2-bromo-6-alkylaminoNDI moiety was used as singlet energy donor and the spin converter, whereas 2,6-dialkylaminoNDI was used as the singlet/triplet energy acceptor. This unique structural protocol and thus alignment of the energy levels ensures the competing ISC and FRET in the triad. The photophysical properties of the triad and the reference compounds were studied with steady-state UV-vis absorption spectra, fluorescence spectra, nanosecond transient absorption spectra, cyclic voltammetry, and DFT/TDDFT calculations. FRET was confirmed with steady-state UV-vis absorption and fluorescence spectroscopy. Intramolecular electron transfer was observed in polar solvents, demonstrated by the quenching of both the fluorescence and triplet state of the energy acceptor. Nanosecond transient absorption spectroscopy shows that the T1 state of the triad is exclusively localized on the 2,6-dialkylaminoNDI moiety in the triad upon selective photoexcitation into the energy donor, which indicates the intramolecular triplet state energy transfer. The intermolecular triplet state energy transfer between the two reference compounds was investigated with nanosecond transient absorption spectroscopy. The photophysical properties were rationalized by TDDFT calculations. PMID:25919420

  5. Manipulating rogue wave triplet in optical waveguides through tapering

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Rama [Department of Physics, DAV University, Jalandhar 144008 (India); Kumar, C.N., E-mail: cnkumar@pu.ac.in [Department of Physics, Panjab University, Chandigarh 160014 (India); Vyas, Vivek M. [Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600 113 (India); Panigrahi, Prasanta K., E-mail: pprasanta@iiserkol.ac.in [Indian Institute of Science Education and Research – Kolkata, Mohanpur, Nadia 741252 (India)

    2015-02-06

    Taking account of the results of the paper, published in [21] (Chabchoub and Akhmediev, 2013), containing experimental generation of rogue wave triplets in the water tank, we demonstrate a theoretical approach to coherently control the rogue wave triplet dynamics and spectral spread in a tapered index optical waveguide. The relative distance between the successive waves of the triplet, along both longitudinal and transverse axes, can be manipulated by modulating the tapering of the waveguide. This not only significantly enhances the possibility of observing these statistically rare events in the waveguide, but can also controllably amplify the intensity and spectral spread, the desired features for supercontinuum generation. The controlling of real Riccati parameter intrinsically arises from the allowed phase variation of the self-similar solutions of the nonlinear Schrödinger equation. - Highlights: • Manipulating rogue wave triplets in GNLSE using Riccati parameter is outlined. • Symmetric transformations used to scale mutual spacing in a triplet. • Results presented for sech{sup 2}-type tapered waveguides.

  6. Photosensitized reactions initiated by 6-carboxypterin: singlet and triplet reactivity.

    Science.gov (United States)

    Tinel, L; Rossignol, S; Ciuraru, R; Dumas, S; George, C

    2016-06-22

    Pterins, derivatives of 2-aminopteridin-4(3H)-one, are natural photosensitizers, common to many biological systems. Indications that these photosensitizers are also present in the sea-surface microlayer motivated the study of the photophysical and photochemical properties of 6-carboxypterin (CPT), which was chosen as a model for this group of photoactive compounds. The kinetics of excited CPT in the singlet and triplet state in the presence of halides and organics were studied in aqueous solutions at neutral pH by means of steady-state fluorescence and laser-flash photolysis. The fluorescence of CPT was efficiently quenched by two halides (iodide and bromide) and by four carboxylic acids (lactic, malonic, propionic and citric acid) with reaction rates close to the diffusion-controlled limit. In the triplet state, the triplet absorption spectrum was measured and its pH dependence was studied. The triplet state of CPT showed relatively high reactivity towards iodide, but no reaction with bromide or chloride could be observed. No singlet or triplet state quenching in the presence of limonene could be measured. A reaction mechanism is proposed, initiated by electron transfer from the quencher to the excited photosensitizer. This type of photo-induced reaction in the sea-surface microlayer has the potential to trigger the production of many oxidized species, including halogen atoms, in the bulk and gaseous phases. PMID:27296228

  7. [Investigation of the microstructure of biological systems by triplet label].

    Science.gov (United States)

    Kotel'niko, A I; Kuznetsov, S N; Fogel', V R; Likhtenshteĭn, G I

    1979-01-01

    A method for investigating the microstruct and dynamics of biological systems by means of triplet-excited molecules is suggested. The method is based on the phenomenon of triplet excitation disactivation by exchange-resonance triplet-triplet energy transfer to the acceptor or by intercombination conversion induced by interaction of an excited molecule with a paramagnetic center. The disactivation efficiency was measured by registrating the phosphorescense decay kinetics. The interaction of the triplet label eosin isothiocyanate, covalently coupled with albumine, lysozyme, sarcoplasmic reticulum membrane and Ca-Mg-dependent sarcoplasmic reticulum ATPase, with O2, the stable nitroxide radicals and ions of Mn2+ was investigated to analyse the potentialities of this method. As a model system the eosin phosphorescence quenching by the same quenchers in glycerine-aguaous solutions was studied. The method permits to investigate the microviscosity and microstructure of biological objects in the label attached region on interaction of the label with a sound-quencher with constants being 10(4) divided by 10(9) M-1 sec-1 and to measure the lateral diffusion of molecules in highly viscosity media (10 divided by 10(5) santypuas). PMID:223037

  8. Long-Lived, Colour-Triplet Scalars from Unnaturalness

    CERN Document Server

    Barnard, James; Gherghetta, Tony; Spray, Andrew

    2015-01-01

    Long-lived, colour-triplet scalars are a generic prediction of unnatural, or split, composite Higgs models where the spontaneous global-symmetry breaking scale $f \\gtrsim 10$ TeV and an unbroken $SU(5)$ symmetry is preserved. Since the triplet scalars are pseudo Nambu-Goldstone bosons they are split from the much heavier composite-sector resonances and are the lightest exotic, coloured states. This makes them ideal to search for at colliders. Due to discrete symmetries the triplet scalar decays via a dimension-six term and given the large suppression scale $f$ is often metastable. We show that existing searches for collider-stable R-hadrons from Run-I at the LHC forbid a triplet scalar mass below 845 GeV, whereas with $300\\,\\mathrm{fb}^{-1}$ at 13 TeV triplet scalar masses up to 1.4 TeV can be discovered. For shorter lifetimes displaced-vertex searches provide a discovery reach of up to 1.8 TeV. In addition we present exclusion and discovery reaches of future hadron colliders as well as indirect limits that a...

  9. Rates and singlet/triplet ratios from TADF transients

    CERN Document Server

    Nelson, Mitchell C

    2016-01-01

    Thermally activated delayed fluorescence has been reported in a number of OLED emitter materials engineered to have low singlet-triplet energy gaps. Here we derive closed solutions for steady state and transient behaviors and apply these results to data provided in recent reports. Earlier work has used yields, rates and a supplied forward crossing rate to estimate the reverse crossing rate and then obtain the singlet-triplet energy gap in a log-linear fit. In this work we use only the system relaxation times and obtain all five of the system constants: the singlet and triplet relaxation rates, the forward and reverse crossing rates and the singlet-triplet energy gap. These are then used to calculate the fluorescent/phosphorescent ratio and the singlet/triplet population ratio. Good fits are obtained for data from 4CzIPN and from the excimer m-MTDATA:t-Bu-PBD and the results appear to be consistent with the reported behaviors of OLEDS using these materials.

  10. Fat Branes, Orbifolds and Doublet-Triplet Splitting

    CERN Document Server

    Haba, N; Haba, Naoyuki; Maru, Nobuhito

    2003-01-01

    A simple higher dimensional mechanism of the doublet-triplet splitting is presented in a five dimensional supersymmetric SU(5) GUT on S^1/Z_2. The splitting of multiplets is realized by a VEV of the adjoint chiral superfield which breaks SU(5) gauge symmetry. Depending on the sign of the VEV, zero mode Higgs doublets and triplets are localized on the either side of the fixed points. The mass splitting is realized due to the difference of magnitudes of the overlap with a brane localized or a bulk singlet field. No unnatural fine-tuning of parameters is needed. The proton stability is ensured by locality {em without symmetries}. As well as a conventional mass splitting solution, it is shown that the weak scale Higgs triplet is consistent with the proton stability. This result might provide an alternative signature of GUT in future collider experiments.

  11. Leptogenesis, radiative neutrino masses and inert Higgs triplet dark matter

    Science.gov (United States)

    Lu, Wen-Bin; Gu, Pei-Hong

    2016-05-01

    We extend the standard model by three types of inert fields including Majorana fermion singlets/triplets, real Higgs singlets/triplets and leptonic Higgs doublets. In the presence of a softly broken lepton number and an exactly conserved Z2 discrete symmetry, these inert fields together can mediate a one-loop diagram for a Majorana neutrino mass generation. The heavier inert fields can decay to realize a successful leptogenesis while the lightest inert field can provide a stable dark matter candidate. As an example, we demonstrate the leptogenesis by the inert Higgs doublet decays. We also perform a systematic study on the inert Higgs triplet dark matter scenario where the interference between the gauge and Higgs portal interactions can significantly affect the dark matter properties.

  12. Strong electroweak phase transition from Supersymmetric Custodial Triplets

    CERN Document Server

    Garcia-Pepin, Mateo

    2016-01-01

    The Supersymmetric Custodial Triplet Model, a supersymmetric generalization of the Georgi-Machacek model, has proven to be an interesting modification of the MSSM. It extends the MSSM Higgs sector by three extra SU(2)L triplets in such a way that approximate custodial invariance is preserved and rho-parameter deviations are kept under control. By means of a sizeable triplet contribution to electroweak breaking the model is able to generate a barrier at tree level between the false vacuum and the electroweak one. This will result in a strong first order phase transition for an important region of the parameter space. We also look at the gravitational waves that could be generated as a result of the phase transition and show how future interferometers could be used as a probe of the model.

  13. Lepton Flavor Violation in the singlet-triplet scotogenic model

    CERN Document Server

    Rocha-Moran, Paulina

    2016-01-01

    We investigate lepton flavor violation (LFV) in the the singlet-triplet scotogenic model in which neutrinos acquire non-zero masses at the 1-loop level. In contrast to the most popular variant of this setup, the singlet scotogenic model, this version includes a triplet fermion as well as a triplet scalar, leading to a scenario with a richer dark matter phenomenology. Taking into account results from neutrino oscillation experiments, we explore some aspects of the LFV phenomenology of the model. In particular, we study the relative weight of the dipole operators with respect to other contributions to the LFV amplitudes and determine the most constraining observables. We show that in large portions of the parameter space, the most promising experimental perspectives are found for LFV 3-body decays and for coherent $\\mu-e$ conversion in nuclei.

  14. Leptogenesis, radiative neutrino masses and inert Higgs triplet dark matter

    CERN Document Server

    Lu, Wen-Bin

    2016-01-01

    We extend the standard model by three types of inert fields including Majorana fermion singlets/triplets, real Higgs singlets/triplets and leptonic Higgs doublets. In the presence of a softly broken lepton number and an exactly conserved Z_2 discrete symmetry, these inert fields together can mediate a one-loop diagram for a Majorana neutrino mass generation. The heavier inert fields can decay to realize a successful leptogenesis while the lightest inert field can provide a stable dark matter candidate. As an example, we demonstrate the leptogenesis by the inert Higgs doublet decays. We also perform a systematic study on the inert Higgs triplet dark matter scenario where the interference between the gauge and Higgs portal interactions can significantly affect the dark matter properties.

  15. Topological Vortices in a Spin-Triplet Superconductor

    Institute of Scientific and Technical Information of China (English)

    REN Ji-Rong; WEI Shao-Wen; XU Dong-Hui; DUAN Yi-Shi

    2008-01-01

    Based on the complex three-component order parameter model of a spin-triplet superconductor, by using the φ-mapping theory, we derive a new equation describing the distribution of the magnetic field for vortices, which canbe reduced to the modified London equation in the case of |ψ2|2 =|ψ3|2= 0 and W1l=1. A magnetic flux quantization condition for vortices in a spin-triplet superconductor is also derived, which is topological-invariant. Furthermore, the branch processes during the evolution of the vortices in a spin-triplet superconductor are discussed. We also point out that the sum of the magnetic flux quantization that those vortices carried is 2nΦ0(Φ0 is the unit magnetic flux), that is to say, the sum of winding number is even, which needs to be proved by experiment.

  16. Triplet State Resonance Raman Spectrum of all-trans-diphenylbutadiene

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Grossman, W.E.L.; Killough, P.M;

    1984-01-01

    The resonance Raman spectrum of all-trans-diphenylbutadiene (DPB) in its ground state and the resonance Raman spectrum (RRS) of DPB in its short-lived electronically excited triplet state are reported. Transient spectra were obtained by a pump-probe technique using two pulsed lasers....... The preresonance spectrum of the ground state is not significantly changed from that of the nonresonance spectrum. In the resonance spectrum of the triplet state the double-bond stretching mode of the butadiene part is shifted by 43 cm-1 downward to 1582 cm-1 whereas the single-bond stretching mode is essentially...

  17. CHROMOSPHERIC POLARIZATION IN THE PHOTOSPHERIC SOLAR OXYGEN INFRARED TRIPLET

    Energy Technology Data Exchange (ETDEWEB)

    Del Pino Alemán, Tanausú; Trujillo Bueno, Javier [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain)

    2015-07-20

    We present multilevel radiative transfer modeling of the scattering polarization observed in the solar O i infrared triplet around 777 nm. We demonstrate that the scattering polarization pattern observed on the solar disk forms in the chromosphere, far above the photospheric region where the bulk of the emergent intensity profiles originate. We investigate the sensitivity of the polarization pattern to the thermal structure of the solar atmosphere and to the presence of weak magnetic fields (10{sup −2}–100 G) through the Hanle effect, showing that the scattering polarization signals of the oxygen infrared triplet encode information on the magnetism of the solar chromosphere.

  18. Chromospheric Polarization in the Photospheric Solar Oxygen Infrared Triplet

    CERN Document Server

    Alemán, T del Pino

    2015-01-01

    We present multilevel radiative transfer modeling of the scattering polarization observed in the solar O I infrared triplet around 777 nm. We demonstrate that the scattering polarization pattern observed on the solar disk forms in the chromosphere, far above the photospheric region where the bulk of the emergent intensity profiles originates. We study the sensitivity of the polarization pattern to the thermal structure of the solar atmosphere and to the presence of weak magnetic fields (0.01 - 100 G) through the Hanle effect, showing that the scattering polarization signals of the oxygen infrared triplet encode information on the magnetism of the solar chromosphere.

  19. Chromospheric Polarization in the Photospheric Solar Oxygen Infrared Triplet

    Science.gov (United States)

    Del Pino Alemán, Tanausú; Trujillo Bueno, Javier

    2015-07-01

    We present multilevel radiative transfer modeling of the scattering polarization observed in the solar O i infrared triplet around 777 nm. We demonstrate that the scattering polarization pattern observed on the solar disk forms in the chromosphere, far above the photospheric region where the bulk of the emergent intensity profiles originate. We investigate the sensitivity of the polarization pattern to the thermal structure of the solar atmosphere and to the presence of weak magnetic fields (10-2-100 G) through the Hanle effect, showing that the scattering polarization signals of the oxygen infrared triplet encode information on the magnetism of the solar chromosphere.

  20. Non-conventional halide oxidation pathways : oxidation by imidazole triplet and surface specific oxidation by ozone

    Science.gov (United States)

    Ammann, Markus; Corral-Arroyo, Pablo; Aellig, Raphael; Orlando, Fabrizio; Lee, Ming-Tao; Artiglia, Luca

    2016-04-01

    Oxidation of halide ions (chloride, bromide, iodide) are the starting point of halogen release mechanisms out of sea water, marine aerosol or other halide containing continental aerosols. Slow oxidation of chloride and bromide by ozone in the bulk aqueous phase is of limited relevance. Faster surface specific oxidation has been suggested based on heterogeneous kinetics experiments. We provide first insight into very efficient bromide oxidation by ozone at the aqueous solution - air interface by surface sensitive X-ray photoelectron spectroscopy indicating significant build-up of an oxidized intermediate at the surface within millisecond time scales. The second source of oxidants in the condensed we have considered is the absorption of light by triplet forming photosensitizers at wavelengths longer than needed for direct photolysis and radical formation. We have performed coated wall flow tube experiments with mixtures of citric acid (CA) and imidazole-2-carboxaldehyde (IC) to represent secondary organic material rich marine aerosol. The halide ions bromide and iodide have been observed to act as efficient electron donors leading to their oxidation, HO2 formation and finally release of molecular halogen compounds. The photosensitization of imidazole-2-carboxaldehyde (IC) involves a well-known mechanism where the triplet excited state of IC is reduced by citric acid to a reduced ketyl radical that reacts with halide ions. A competition kinetics approach has been used to evaluate the rate limiting steps and to assess the significance of this source of halogens to the gas phase.

  1. High-efficiency fluorescent organic light-emitting diodes enabled by triplet-triplet annihilation and horizontal emitter orientation

    Energy Technology Data Exchange (ETDEWEB)

    Mayr, Christian, E-mail: Christian.Mayr@physik.uni-augsburg.de; Schmidt, Tobias D.; Brütting, Wolfgang, E-mail: Wolfgang.Bruetting@physik.uni-augsburg.de [Institute of Physics, University of Augsburg, 86135 Augsburg (Germany)

    2014-11-03

    A green organic light-emitting diode with the fluorescent emitter Coumarin 545T shows an external quantum efficiency (η{sub EQE}) of 6.9%, clearly exceeding the classical limit of 5% for fluorescent emitters. The analysis of the angular dependent photoluminescence spectrum of the emission layer reveals that 86% of the transition dipole moments are horizontally oriented. Furthermore, transient electroluminescence measurements demonstrate the presence of a delayed emission originating from triplet-triplet annihilation. A simulation based efficiency analysis reveals quantitatively the origin for the high η{sub EQE}: a radiative exciton fraction higher than 25% and a light-outcoupling efficiency of nearly 30%.

  2. X-Shooter spectroscopy of young stellar objects III. Photospheric and chromospheric properties of Class III objects

    CERN Document Server

    Stelzer, B; Alcala, J M; Manara, C F; Biazzo, K; Covino, E; Rigliaco, E; Testi, L; Covino, S; D'Elia, V

    2013-01-01

    We analyzed X-Shooter/VLT spectra of 24 ClassIII sources from three nearby star-forming regions (sigmaOrionis, LupusIII, and TWHya). We determined the effective temperature, surface gravity, rotational velocity, and radial velocity by comparing the observed spectra with synthetic BT-Settl model spectra. We investigated in detail the emission lines emerging from the stellar chromospheres and combined these data with archival X-ray data to allow for a comparison between chromospheric and coronal emissions. Both X-ray and Halpha luminosity as measured in terms of the bolometric luminosity are independent of the effective temperature for early-M stars but decline toward the end of the spectral M sequence. For the saturated early-M stars the average emission level is almost one dex higher for X-rays than for Halpha: log(L_x/L_bol) = -2.85 +- 0.36 vs. log(L_Halpha/L_bol) = -3.72 +- 0.21. When all chromospheric emission lines (including the Balmer series up to H11, CaII HK, the CaII infrared triplet, and several HeI...

  3. Radiative neutrino model with an inert triplet scalar

    Science.gov (United States)

    Okada, Hiroshi; Orikasa, Yuta

    2016-09-01

    We study a one-loop induced radiative neutrino model with an inert isospin triplet scalar field in the general framework of U (1 )Y , in which we discuss current neutrino oscillation data, lepton flavor violations, a muon anomalous magnetic moment, and a dark matter candidate depending on the number of hypercharges. We show global analysis combining all the constraints and discuss the model.

  4. Vector-like quarks with a scalar triplet

    CERN Document Server

    Leskow, Estefania Coluccio; de la Puente, Alejandro

    2014-01-01

    We study a model independent extension to the Standard Model with an addi- tional real scalar triplet, {\\Sigma}, and a single vector-like quark, T . This class of models appear naturally in extensions of the Littlest Higgs model that incorporate dark matter without the need of T -parity. We assume that the triplet does not develop a vacuum expectation value and that all dimension five operators coupling the triplet to Standard Model fields and the vector-like quarks are parametrized by the scale {\\Lambda} at which we expect new physics to arise. We introduce new non-renormalizable interactions between the new scalar sector and fermion sector that allow mixing between the Standard Model third generation up-type quark and the vector-like quark in a way that leads to the cancellation of the leading quadratic divergences to the one-loop corrections to the mass of the Higgs boson. Within this framework, new de- cay modes of the vector-like quark to the real scalar triplet and SM particles arise and bring forth an ...

  5. Stability of singlet and triplet trions in carbon nanotubes

    DEFF Research Database (Denmark)

    Rønnow, Troels Frimodt; Pedersen, Thomas Garm; Cornean, Horia

    2009-01-01

    We investigate singlet and triplet trion states in semiconducting carbon nanotubes using a one-dimensional model. It is concluded that singlet trion states in bind up to 13.5% stronger than exciton states, and that they lower the optical transition energy with up to 50% of the tight binding band...

  6. Dark Matter from the Supersymmetric Custodial Triplet Model

    CERN Document Server

    Delgado, Antonio; Ostdiek, Bryan; Quiros, Mariano

    2015-01-01

    The Supersymmetric Custodial Triplet Model (SCTM) adds to the particle content of the MSSM three $SU(2)_L$ triplet chiral superfields with hypercharge $Y=(0,\\pm1)$. At the superpotential level the model respects a global $SU(2)_L \\otimes SU(2)_R$ symmetry only broken by the Yukawa interactions. The pattern of vacuum expectation values of the neutral doublet and triplet scalar fields depends on the symmetry pattern of the Higgs soft breaking masses. We study the cases where this symmetry is maintained in the Higgs sector, and when it is broken only by the two doublets attaining different vacuum expectation values. In the former case, the symmetry is spontaneously broken down to the vectorial subgroup $SU(2)_V$ and the $\\rho$ parameter is protected by the custodial symmetry. However in both situations the $\\rho$ parameter is protected at tree level, allowing for light triplet scalars with large vacuum expectation values. We find that over a large range of parameter space, a light neutralino can supply the corre...

  7. Stability of singlet and triplet trions in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ronnow, Troels F. [Department of Physics and Nanotechnology, Skjernvej 4C, 9220 Aalborg Ost (Denmark)], E-mail: tfr@nanophysics.dk; Pedersen, Thomas G. [Department of Physics and Nanotechnology, Skjernvej 4C, 9220 Aalborg Ost (Denmark)], E-mail: tgp@nano.aau.dk; Cornean, Horia D. [Department of Mathematical Sciences, Frederik Bajers Vej 7G, 9220 Aalborg Ost (Denmark)], E-mail: cornean@math.aau.dk

    2009-04-06

    We investigate singlet and triplet trion states in semiconducting carbon nanotubes using a one-dimensional model. It is concluded that singlet trion states in bind up to 13.6% stronger than exciton states, and that they lower the optical transition energy with up to 50% of the tight binding band gap energy.

  8. Stability of singlet and triplet trions in carbon nanotubes

    International Nuclear Information System (INIS)

    We investigate singlet and triplet trion states in semiconducting carbon nanotubes using a one-dimensional model. It is concluded that singlet trion states in bind up to 13.6% stronger than exciton states, and that they lower the optical transition energy with up to 50% of the tight binding band gap energy.

  9. Properties of the Triplet State of Coumarin Substituted Compounds

    Science.gov (United States)

    Bryantseva, N. G.; Gadirov, R. M.; Nikonov, S. Yu.; Sokolova, I. V.

    2015-03-01

    The absorption spectra of the triplet excited state of coumarin sensitizers are investigated both theoretically and experimentally. The most intense triplet-triplet (TT) absorption bands are determined. The experimental spectra of the T-T absorption are compared with the theoretical T-T transitions. The phosphorescence spectra of five compounds are measured at a temperature of 77 K. The quantum phosphorescence yield is determined by the method of comparison with an etalon (8-methoxypsoralen). The phosphorescence lifetime is determined for the examined molecules at a temperature of 77 K. For 3,4-phenyl-4',5'-cyclohexylpsoralen, 4'-methyl-3,4-cycloheptylpsoralen, and 4'5'-dimethyl-3,4-cyclohexylpsoralen compounds, this time is equal to 1.1, 1.25, and 2.5 s, respectively. The main energy deactivation channel for all examined compounds is the phosphorescence. The positions of the lower excited triplet states, calculated by the quantum-chemical method of intermediate neglect of differential overlap with spectroscopic parameterization (INDO/S), are confirmed by the available experimental data.

  10. Triplet states at an O vacancy in alpha-quartz

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2002-01-01

    The energy landscape of an alpha-quartz O vacancy in the lowest triplet state is investigated. Four local minima are identified and geometries, total energies, and electron paramagnetic resonance (EPR) parameters are obtained. On the basis of calculated values for the magnetic dipole interaction...

  11. Vector-like quarks with a scalar triplet

    Directory of Open Access Journals (Sweden)

    Estefania Coluccio Leskow

    2015-04-01

    Full Text Available We study a minimal extension to the Standard Model with an additional real scalar triplet, Σ, and a single vector-like quark, T. This class of models appear naturally in extensions of the Littlest Higgs model that incorporate dark matter without the need of T-parity. We assume the limit that the triplet does not develop a vacuum expectation value and that all dimension five operators coupling the triplet to Standard Model fields and the vector-like quarks are characterized by the scale Λ at which we expect new physics to arise. We introduce new non-renormalizable interactions between the new scalar sector and fermion sector that allow mixing between the Standard Model third generation up-type quark and the vector-like quark in a way that leads to the cancellation of the leading quadratic divergences to the one-loop corrections from the top quark to the mass of the Higgs boson. Within this framework, new decay modes of the vector-like quark to the real scalar triplet and SM particles arise and bring forth an opportunity to probe this model with existing and future LHC data. We contrast constraints from direct colliders searches with low energy precision measurements and find that heavy vector-like top quarks with a mass as low as 650 GeV are consistent with current experimental constraints in models where new physics arises at scales below 2 TeV.

  12. The Ca II triplet in red giant spectra: [Fe/H] determinations and the role of [Ca/Fe

    CERN Document Server

    Da Costa, G S

    2015-01-01

    Measurements are presented and analyzed of the strength of the Ca II triplet lines in red giants in Galactic globular and open clusters, and in a sample of red giants in the LMC disk that have significantly different [Ca/Fe] abundance ratios to the Galactic objects. The Galactic objects are used to generate a calibration between Ca II triplet line strength and [Fe/H], which is then used to estimate [Fe/H]_CaT for the LMC stars. The values are then compared with the [Fe/H]_spec determinations from high dispersion spectroscopy. After allowance for a small systematic offset the two abundance determinations are in excellent agreement. Further, as found in earlier studies, e.g., Battaglia et al. (2008), the difference is only a very weak function of the [Ca/Fe] ratio. For example, changing [Ca/Fe] from +0.3 to -0.2 causes the Ca II based abundance to underestimate [Fe/H]_spec by only ~0.15 dex, assuming a Galactic calibration. Consequently, the Ca II triplet approach to metallicity determinations can be used witho...

  13. Spontaneous fluctuations of transition dipole moment orientation in OLED triplet emitters

    CERN Document Server

    Steiner, Florian; Vogelsang, Jan; Lupton, John M

    2015-01-01

    The efficiency of an organic light-emitting diode (OLED) depends on the microscopic orientation of transition dipole moments of the molecular emitters. The most effective materials used for light generation have threefold symmetry, which prohibit a priori determination of dipole orientation due to the degeneracy of the fundamental transition. Single-molecule spectroscopy reveals that the model triplet emitter tris(2-phenylisoquinoline)iridium(III) (Ir(piq)3) does not behave as a linear dipole, radiating with lower polarization anisotropy than expected. Spontaneous symmetry breaking occurs in the excited state, leading to a random selection of one of the three ligands to form a charge transfer state with the metal. This non-deterministic localization is revealed in switching of the degree of linear polarization of phosphorescence. Polarization scrambling likely raises out-coupling efficiency and should be taken into account when deriving molecular orientation of the guest emitter within the OLED host from ense...

  14. Intramolecular triplet energy transfer via higher triplet excited state during stepwise two-color two-laser irradiation.

    Science.gov (United States)

    Oseki, Yosuke; Fujitsuka, Mamoru; Sakamoto, Masanori; Majima, Tetsuro

    2007-10-01

    We studied the energy transfer processes in the molecular array consisting of pyrene (Py), biphenyl (Ph2), and bisphthalimidethiophene (ImT), (Py-Ph2)2-ImT, during two-color two-laser flash photolysis (2-LFP). The first laser irradiation predominantly generates ImT in the lowest triplet excited state (ImT(T1)) because of the efficient singlet energy transfer from Py in the lowest singlet excited state to ImT and, then, intersystem crossing of ImT. ImT(T1) was excited to the higher triplet excited state (Tn) with the second laser irradiation. Then, the triplet energy was rapidly transferred to Py via a two-step triplet energy transfer (TET) process through Ph2. The efficient generation of Py(T1) was suggested from the nanosecond-picosecond 2-LFP. The back-TET from Py(T1) to ImT was observed for several tens of microseconds after the second laser irradiation. The estimated intramolecular TET rate from Py(T1) to ImT was as slow as 3.1 x 104 s-1. Hence, long-lived Py(T1) was selectively and efficiently produced during the 2-LFP.

  15. PROBE FOR THE FORMATION RATIO BETWEEN EXCITED TRIPLETS AND SINGLETS AS GENERATED IN POLYMER LIGHT-EMITTING DIODES

    Institute of Scientific and Technical Information of China (English)

    Jing-ying Zhang; Shi-dong Kan; Yu-guang Ma; Jia-cong Shen

    2001-01-01

    The electroluminescence (EL) produced by a highly luminescent phosphorescent dye Cu4(C≡CPh)4L2 (L = 1.8-bis(di-phenylphosphino)-3,6-dioxaoctane, Cu4) doped polymer as emitting layer is reported. The effects of the charge injection balance on the polymers, in particular, poly(N-vinylcarbazole) (PVK) have been studied by using photoluminescence and electroluminescence spectroscopy. Changes in the emission spectra demonstrate the influence of the charge injection balance on the formation ratio of triplet and singlet excitons. This provides a new technical approach to realize the color patterning in polymer LEDs.

  16. Mixed ligand complexes of alkaline earth metals: Part XII. Mg(II, Ca(II, Sr(II and Ba(II complexes with 5-chlorosalicylaldehyde and salicylaldehyde or hydroxyaromatic ketones

    Directory of Open Access Journals (Sweden)

    MITHLESH AGRAWAL

    2002-04-01

    Full Text Available The reactions of alkaline earth metal chlorides with 5-chlorosalicylaldehyde and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been carried out in 1 : 1 : 1 mole ratio and the mixed ligand complexes of the type MLL’(H2O2 (where M = Mg(II, Ca(II, Sr(II and Ba(II, HL = 5-chlorosalicylaldehyde and HL’ = salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been isolated. These complexes were characterized by TLC, conductance measurements, IR and 1H-NMR spectra.

  17. Heats of Formation of Triplet Ethylene, Ethylidene, and Acetylene

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, M.T.; Matus, M.H.; Lester Jr, W.A.; Dixon, David A.

    2007-06-28

    Heats of formation of the lowest triplet state of ethylene and the ground triplet state of ethylidene have been predicted by high level electronic structure calculations. Total atomization energies obtained from coupled-cluster CCSD(T) energies extrapolated to the complete basis set limit using correlation consistent basis sets (CBS), plus additional corrections predict the following heats of formation in kcal/mol: Delta H0f(C2H4,3A1) = 80.1 at 0 K and 78.5 at 298 K, and Delta H0f(CH3CH,3A") = 86.8 at 0 K and 85.1 at 298 K, with an error of less than +-1.0 kcal/mol. The vertical and adiabatic singlet-triplet separation energies of ethylene were calculated as Delta ES-T,vert = 104.1 and Delta ES-T,adia = 65.8 kcal/mol. These results are in excellent agreement with recent quantum Monte Carlo (DMC) values of 103.5 +- 0.3 and 66.4 +- 0.3 kcal/mol. Both sets of computational values differ from the experimental estimate of 58 +- 3 kcal/mol for the adiabatic splitting. The computed singlet-triplet gap at 0 K for acetylene is Delta ES-T,adia(C2H2) = 90.5 kcal/mol, which is in notable disagreement with the experimental value of 82.6 kcal/mol. The heat of formation of the triplet is Delta H0f(C2H2,3B2) = 145.3 kcal/mol. There is a systematic underestimation of the singlet-triplet gaps in recent photodecomposition experiments by ~;;7 to 8 kcal/mol. For vinylidene, we predict Delta H0f(H2CC,1A1) = 98.8 kcal/mol at 298 K (exptl. 100.3 +- 4.0), Delta H0f(H2CC,3B2) = 146.2 at 298 K, and an energy gap Delta ES-T-adia(H2CC) = 47.7 kcal/mol.

  18. Fine-Tuning of β-Substitution to Modulate the Lowest Triplet Excited States: A Bioinspired Approach to Design Phosphorescent Metalloporphyrinoids.

    Science.gov (United States)

    Ke, Xian-Sheng; Zhao, Hongmei; Zou, Xiaoran; Ning, Yingying; Cheng, Xin; Su, Hongmei; Zhang, Jun-Long

    2015-08-26

    Learning nature's approach to modulate photophysical properties of NIR porphyrinoids by fine-tuning β-substituents including the number and position, in a manner similar to naturally occurring chlorophylls, has the potential to circumvent the disadvantages of traditional "extended π-conjugation" strategy such as stability, molecular size, solubility, and undesirable π-π stacking. Here we show that such subtle structural changes in Pt(II) or Pd(II) cis/trans-porphodilactones (termed by cis/trans-Pt/Pd) influence photophysical properties of the lowest triplet excited states including phosphorescence, Stokes shifts, and even photosensitization ability in triplet-triplet annihilation reactions with rubrene. Prominently, the overall upconversion capability (η, η = ε·Φ(UC)) of Pd or Pt trans-complex is 10(4) times higher than that of cis-analogue. Nanosecond time-resolved infrared (TR-IR) spectroscopy experiments showed larger frequency shift of ν(C═O) bands (ca. 10 cm(-1)) of cis-complexes than those of trans-complexes in the triplet excited states. These spectral features, combining with TD-DFT calculations, suggest the strong electronic coupling between the lactone moieties and the main porphyrin chromophores and thus the importance of precisely positioning β-substituents by mimicking chlorophylls, as an alternative to "extended π-conjugation", in designing NIR active porphyrinoids. PMID:26247480

  19. On-chip generation of photon-triplet states.

    Science.gov (United States)

    Krapick, Stephan; Brecht, Benjamin; Herrmann, Harald; Quiring, Viktor; Silberhorn, Christine

    2016-02-01

    Efficient sources of many-partite non-classical states are key for the advancement of quantum technologies and for the fundamental testing of quantum mechanics. We demonstrate the generation of time-correlated photon triplets at telecom wavelengths via pulsed cascaded parametric down-conversion in a monolithically integrated source. By detecting the generated states with success probabilities of (6.25 ± 1.09) × 10(-11) per pump pulse at injected powers as low as 10 μW, we benchmark the efficiency of the complete system and deduce its high potential for scalability. Our source is unprecedentedly long-term stable, it overcomes interface losses intrinsically due to its monolithic architecture, and the photon-triplet states dominate uncorrelated noise significantly. These results mark crucial progress towards the proliferation of robust, scalable, synchronized and miniaturized quantum technology. PMID:26906852

  20. Cooperation within triplets in the rock-paper-scissors game

    Science.gov (United States)

    Hernández, Damián G.; Zanette, Damián H.

    2014-01-01

    We study a population involved in a cyclic game of three strategies - the rock-paper-scissors game - whose agents interact through groups of three individuals (triplets), considering the possibility that two weak agents cooperate and beat a strong one. In a wide range of parameters the system presents a stable heteroclinic cycle, which implies that in a finite population some of the strategies become extinct and others survive. We find that the cooperation within triplets only benefits the survival of the strategy if the cooperation probability is above a certain threshold. We study the survival probabilities of the different strategies as a function of the cooperation parameters through a analytic approximation and compare with simulations, obtaining a good agreement. Results are generalizable to other systems with heteroclinic cycles.

  1. Role of triplet polaron pairs in conjugated polymer photophysics

    Science.gov (United States)

    Wesely, Elizabeth; Rothberg, Lewis; Marchetti, Alfred; Chen, Shaw; Geng, Yanhou; Culligan, Sean

    2007-03-01

    We measure the decay of the long-lived fluorescence of a conjugated oligofluorene at temperatures from 300 K to 20 K. We conclude that nearly all of this emission arises from geminate recombination of photogenerated polaron pairs to reform the singlet exciton, and that charge pair recombination represents a significant contribution to the overall fluorescence quantum yield. The unusual nonmonotonic decay dynamics of the delayed fluorescence can be explained if we assume interconversion between singlet and triplet polaron pairs on the submicrosecond time scale. (˜500 ns.) We are able to model the decay of the delayed fluorescence by assuming activated recombination from a Gaussian energy distribution of singlet polaron pairs centered 0.2 eV below the excited state and having a standard deviation of 0.12 eV. The model is relevant to recent work involving the measurement of singlet-triplet branching ratios and to the yields of electroluminescent devices.

  2. Measuring oxygen pressures using triplet quenching of Pd-porphine

    Science.gov (United States)

    Sinaasappel, Michiel; Ince, C.; Sanderse, E. A.; Bruining, Hajo A.

    1994-02-01

    A non-invasive optical method for measuring free oxygen in vivo is described. The method, introduced by Wilson and co-workers, is based on the quenching of the triplet state of Pd- porphine by oxygen and is described by the Stern-Volmer relation. The quenching of the triplet state is determined by measurement of the phosphorescence decay following excitation by a pulse of light. Measuring decay times has the advantage that they are independent of the changing optical properties of tissue and concentration of the dye. We describe a setup to measure the phosphorescence decay and present the values of Kq and (tau) o as a function of pH and temperature. Furthermore, some experiments on a rat liver and gut are presented.

  3. Theoretical Investigation on Triplet Excitation Energy Transfer in Fluorene Dimer

    Institute of Scientific and Technical Information of China (English)

    Yu-bing Si; Xin-xin Zhong; Wei-wei Zhang; Yi Zhao

    2011-01-01

    Triplet-triplet energy transfer in fluorene dimer is investigated by combining rate theories with electronic structure calculations.The two key parameters for the control of energy transfer,electronic conpling and reorganization energy,are calculated based on the diabatic states constructed by the constrained density functional theory.The fluctuation of the electronic coupling is further revealed by molecular dynamics simulation.Succeedingly,the diagonal and off-diagonal fluctuations of thc Hamiltonian are mapped from the correlation functions of those parameters,and the rate is then estimated both from the perturbation theory and wavepacket diffusion method.The results manifest that both the static and dynamic fluctuations enhance the rate significantly,but the rate from the dynamic fluctuation is smaller than that from the static fluctuation.

  4. Ultrafast photogeneration mechanisms of triplet states in para-hexaphenyl

    OpenAIRE

    Zenz, C.; Cerullo, G.; G. Lanzani; Graupner, W.; Meghdadi, F.; Leising, G.; Silvestri, S

    1999-01-01

    We present femtosecond pump-probe measurements, both conventional and electric field-assisted, on organic light-emitting devices based on para-hexaphenyl. The dominant triplet excition generation mechanism is assigned to nongeminate bimolecular recombination of photogenerated, spin-1/2 polarons. This process is active within a few hundred femtoseconds after photoexcitation and involves about 20% of the initially excited states. At higher photoexcitation densities, we observe an additional tri...

  5. Anomalous Josephson Hall effect in magnet/triplet superconductor junctions

    OpenAIRE

    Yokoyama, Takehito

    2015-01-01

    We investigate anomalous Hall effect in a magnet coupled to a triplet superconductor under phase gradient. It is found that the anomalous Hall supercurrent arises from non-trivial structure of the magnetization. The magnetic structure manifested in the Hall supercurrent is characterized by even order terms of the exchange coupling, essentially different from that discussed in the context of anomalous Hall effect, reflecting the disspationless nature of supercurrent. We also discuss a possible...

  6. Cascade Decays of Triplet Higgs Bosons at LEP2

    CERN Document Server

    Akeroyd, A G

    1998-01-01

    We study the Georgi-Machacek two triplet, one doublet model in the context of LEP2, and show that cascade decays of Higgs bosons to lighter Higgs bosons and a virtual vector boson may play a major role. Such decays would allow the Higgs bosons of this model to escape current searches, and in particular are of great importance for the members of the five-plet which will always decay to the three-plet giving rise to cascade signatures.

  7. Genome-specificity of triplet periodicity of prokaryotic genomes

    International Nuclear Information System (INIS)

    Authors have found that triplet periodicity (TP) is more similar inside genome than between genomes and that TP distribution inside genome corresponds to hypothesis which imply common TP pattern for majority of sequences inside a genome. To test the specificity of TP, the classification of the gene has been carried out to detect the belonging to one genome of the pair. For most pairs, the classification accuracy was more than 85%

  8. Polaron pair mediated triplet generation in polymer/fullerene blends

    KAUST Repository

    Dimitrov, Stoichko D.

    2015-03-04

    Electron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well as spintronic applications relying on organic magnetoresistance. A mechanism for triplet excited state generation in such systems is by recombination of electron-hole pairs. However, the exact charge recombination mechanism, whether geminate or nongeminate and whether it involves spin-state mixing is not well understood. In this work, the dynamics of free charge separation competing with recombination to polymer triplet states is studied in two closely related polymer-fullerene blends with differing polymer fluorination and photovoltaic performance. Using time-resolved laser spectroscopic techniques and quantum chemical calculations, we show that lower charge separation in the fluorinated system is associated with the formation of bound electron-hole pairs, which undergo spin-state mixing on the nanosecond timescale and subsequent geminate recombination to triplet excitons. We find that these bound electron-hole pairs can be dissociated by electric fields.

  9. Sirenomelia in a Nigerian triplet: a case report

    Directory of Open Access Journals (Sweden)

    Wonodi Woroma

    2011-09-01

    Full Text Available Abstract Introduction Sirenomelia, also known as mermaid syndrome, is a very rare fatal congenital abnormality in which the legs are fused together, giving them the appearance of a mermaid's tail. It is commonly associated with abnormal kidney development, genital and rectal abnormalities. A handful of cases have been reported in other parts of the world, however, no cases have previously been reported in a Nigerian neonate. To the best of our knowledge, we believe that this is the first case reported from West Africa and in a triplet. Case presentation A 16-hour-old baby boy, the second of a set of Nigerian triplets, presented to our facility with fusion of the entire lower limbs, imperforate anus, indiscernible genital structures, single umbilical artery and a neural tube defect. His parents were from the Hausa ethnic group and not related. Conclusion Sirenomelia has not been previously described in a set of triplets, and it is hoped that this report from West Africa will give information about the non-racial predilection of this condition.

  10. Renormalization of the Higgs sector in the triplet model

    CERN Document Server

    Aoki, Mayumi; Kikuchi, Mariko; Yagyu, Kei

    2012-01-01

    We study radiative corrections to the mass spectrum and the triple Higgs boson coupling in the model with an additional Y=1 triplet field. In this model, the vacuum expectation value for the triplet field is strongly constrained from the electroweak precision data, under which characteristic mass spectrum appear at the tree level; i.e., $m_{H^{++}}^2-m_{H^+}^2\\simeq m_{H^+}^2-m_A^2$ and $m_A^2\\simeq m_H^2$, where the CP-even ($H$), the CP-odd ($A$) and the doubly-charged ($H^{\\pm\\pm}$) as well as the singly-charged ($H^\\pm$) Higgs bosons are the triplet-like. We evaluate how the tree-level formulae are modified at the one-loop level. The $hhh$ coupling for the standard model-like Higgs boson ($h$) is also calculated at the one-loop level. One-loop corrections to these quantities can be large enough for identification of the model by future precision data at the LHC or the International Linear Collider.

  11. Renormalization of the Higgs sector in the triplet model

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Mayumi [Institute for Theoretical Physics, Kanazawa University, Kanazawa 920-1192 (Japan); Kanemura, Shinya; Kikuchi, Mariko [Department of Physics, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Yagyu, Kei, E-mail: keiyagyu@jodo.sci.u-toyama.ac.jp [Department of Physics, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); National Central University, Physics and Center for Mathematics and Theoretical Physics, No. 300, Jhongda Rd., Jhongli, Taiwan (China)

    2012-08-14

    We study radiative corrections to the mass spectrum and the triple Higgs boson coupling in the model with an additional Y=1 triplet field. In this model, the vacuum expectation value for the triplet field is strongly constrained from the electroweak precision data, under which characteristic mass spectrum appear at the tree level; i.e., m{sub H{sup +}{sup +2}}-m{sub H{sup +2}} Asymptotically-Equal-To m{sub H{sup +2}}-m{sub A}{sup 2} and m{sub A}{sup 2} Asymptotically-Equal-To m{sub H}{sup 2}, where the CP-even (H), the CP-odd (A) and the doubly-charged (H{sup {+-}{+-}}) as well as the singly-charged (H{sup {+-}}) Higgs bosons are the triplet-like. We evaluate how the tree-level formulae are modified at the one-loop level. The hhh coupling for the standard model-like Higgs boson (h) is also calculated at the one-loop level. One-loop corrections to these quantities can be large enough for identification of the model by future precision data at the LHC or the International Linear Collider.

  12. Monochorionic triamniotic triplet pregnancy with a co-triplet fetus discordant for congenital cystic adenomatoid malformation of the lung

    Directory of Open Access Journals (Sweden)

    Ceylan Yavuz

    2005-04-01

    Full Text Available Abstract Background Spontaneous monochorionic triamniotic pregnancy is rare and is at increased risk for pregnancy complications. The presence of an anomalous fetus further complicates the management. Case presentation We present a case of monochorionic triamniotic triplet pregnancy diagnosed at 15 weeks of gestation with one fetus having developed a multicystic lung lesion, suggestive of congenital cystic adenomatoid malformation (CCAM. At 24 weeks, the largest cyst measured 10 mm in diameter. We managed the pregnancy conservatively and delivered three live male fetuses with birth weights 1560 g, 1580 g and 1590 g at 35 weeks of gestation. Two newborns were admitted to the neonatal intensive care unit with respiratory distress, the third one died due to sepsis 7 days postpartum. One of the newborns was discharged healthy at 24 days postpartum. The newborn with CCAM developed a pneumothorax on the right side, recovered after treatment, and was discharged after one month. Computerized tomography (CT of the infant at 3 months demonstrated two cystic lesions in the middle lobe of the right lung measuring 25 mm and 15 mm. A repeat CT of the infant at 6 months showed a 30 mm solitary cystic mass. Conclusion Monochorionic triamniotic triplet pregnancy with a co-triplet fetus discordant for CCAM, present rarely and can be managed conservatively. These findings may help in decision making and counselling of parents.

  13. Excited triplet states as photooxidants in surface waters

    Science.gov (United States)

    Canonica, S.

    2012-12-01

    The chromophoric components of dissolved organic matter (DOM) are generally the main absorbers of sunlight in surface waters and therefore a source of transient reactants under irradiation. Such short-lived species can be relevant for the fate of various classes of chemical contaminants in the aquatic environment. The present contribution focuses on the role of excited triplet states of chromophoric DOM, 3CDOM*, as transient photooxidants initiating the transformation and degradation of organic chemical contaminants. An early study [1] indicated that 3CDOM* may play a dominant role in the photo-induced transformation of electron-rich phenols, a conclusion which was later fortified by the results of transient absorption investigations using aromatic ketones as model photosensitizers [2] and by a recent careful analysis of the effect of oxygen concentration on transformation rates [3]. The variety of aquatic contaminants shown to be affected by triplet-induced oxidation has kept increasing, phenylurea herbicides [4], sulfonamide antibiotics [5] and some phytoestrogens [6] being prominent examples. Recent research has shown that the triplet-induced transformation of specific contaminants, especially aromatic nitrogen compounds, could be inhibited by the presence of DOM, very probably due to its antioxidant moieties [7]. While such moieties are not relevant for the quenching of 3CDOM*, they are expected to react with it in a similar way as the studied contaminants. Analogous reactions can be postulated to occur in liquid or solid phases of the atmospheric environment, as demonstrated in the case of HONO formation [8]. References 1. Canonica, S.; Jans, U.; Stemmler, K.; Hoigné, J. Transformation kinetics of phenols in water: Photosensitization by dissolved natural organic material and aromatic ketones. Environ. Sci. Technol. 1995, 29 (7), 1822-1831. 2. Canonica, S.; Hellrung, B.; Wirz, J. Oxidation of phenols by triplet aromatic ketones in aqueous solution. J. Phys

  14. Line-absorption of He-like triplet lines by Li-like ions: Caveats of using line ratios of triplets for plasma diagnostics

    CERN Document Server

    Mehdipour, M; Raassen, A J J

    2015-01-01

    He-like ions produce distinctive series of triplet lines under various astrophysical conditions. However, this emission can be affected by line-absorption from Li-like ions in the same medium. We investigate this absorption of He-like triplets and present the implications for diagnostics of plasmas in photoionisation equilibrium using the line ratios of the triplets. Our computations are carried out for the O VI and Fe XXIV absorption of the O VII and Fe XXV triplet emission lines, respectively. The fluorescent emission by the Li-like ions and continuum absorption of the He-like ion triplet lines are also investigated. We determine the absorption of the triplet lines as a function of Li-like ion column density and velocity dispersion of the emitting/absorbing medium. We find O VI line-absorption can significantly alter the O VII triplet line ratios in optically-thin plasmas, by primarily absorbing the intercombination lines and to lesser extent the forbidden line. Due to intrinsic line-absorption by O VI insi...

  15. Quark fragmentation into spin-triplet $S$-wave quarkonium

    CERN Document Server

    Bodwin, Geoffrey T; Kim, U-Rae; Lee, Jungil

    2014-01-01

    We compute fragmentation functions for a quark to fragment to a quarkonium through an $S$-wave spin-triplet heavy quark-antiquark pair. We consider both color-singlet and color-octet heavy quark-antiquark ($Q\\bar Q$) pairs. We give results for the case in which the fragmenting quark and the quark that is a constituent of the quarkonium have different flavors and for the case in which these quarks have the same flavors. Our results for the sum over all spin polarizations of the $Q\\bar Q$ pairs confirm previous results. Our results for longitudinally polarized $Q\\bar Q$ pairs are new.

  16. Tunneling Conductance in Normal Metal/Insulator/Triplet Superconductor Junction

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-Wei

    2005-01-01

    Tunneling conductance in normal metal/insulator/triplet superconductor junctions is studied theoretically as a function of the bias voltage at zero temperature and finite temperature. The results show there are zero-bias conductance peak, zero-bias conductance dip and double-minimum structures in the spectra for p-wave superconductor junctions. The existence of such structures in the conductance spectrum can be taken as evidence that the pairing symmetry of Sr2RuO4 is p-wave symmetry.

  17. Status of the LHC inner triplet quadrupole program at Fermilab

    CERN Document Server

    Andreev, N; Bauer, P; Bossert, R; Brandt, J; Carson, J; Caspi, S; Chichili, D R; Chiesa, L; Darve, C; Di Marco, J; Fehér, S; Ghosh, A; Glass, H; Huang, Y; Kerby, J S; Lamm, M J; Markarov, A A; McInturff, A D; Nicol, T H; Nobrega, A; Novitski, I; Ogitsu, T; Orris, D; Ozelis, J P; Page, T; Peterson, T; Rabehl, Roger Jon; Robotham, W; Sabbi, G L; Scanlan, R M; Schlabach, P; Sylvester, C D; Strait, J B; Tartaglia, M; Tompkins, J C; Velev, G V; Yadav, S; Zlobin, A V

    2001-01-01

    Fermilab, in collaboration with LBNL and BNL, is developing a quadrupole for installation in the interaction region inner triplets of the LHC. This magnet is required to have an operating gradient of 215 T/m across a 70 mm coil bore, and operates in superfluid helium at 1.9 K. A 2 m magnet program addressing mechanical, magnetic, quench protection, and thermal issues associated with the design was completed earlier this year, and production of the first full length, cryostatted prototype magnet is underway. This paper summarizes the conclusions of the 2 m program, and the design and status of the first full-length prototype magnet. (11 refs).

  18. String theory triplets and higher-spin curvatures

    CERN Document Server

    Francia, Dario

    2010-01-01

    Unconstrained local Lagrangians for higher-spin gauge theories are bound to involve auxiliary fields, whose integration in the partition function generates geometric, effective actions expressed in terms of curvatures. When applied to the triplets, emerging from the tensionless limit of open string field theory, the same procedure yields interesting alternative forms of geometric Lagrangians, whose rather simple pattern is essentially the same for bosons and fermions. This shows that higher-spin curvatures might play a role in the dynamics, regardless of whether the Fronsdal-Labastida constraints are assumed or not.

  19. Triplets contribute to both an increase and loss in fluorescent yield in organic light emitting diodes.

    Science.gov (United States)

    Zhang, Yifan; Forrest, Stephen R

    2012-06-29

    Nonradiative triplets in fluorescent organic light emitting diodes (OLEDs) can lead to increased efficiency through triplet-triplet annihilation, or to decreased efficiency due to singlet-triplet annihilation. We study the tradeoff between the two processes from the electroluminescence transients of an OLED comprising a tetraphenyldibenzoperiflanthene (DBP) doped rubrene emissive layer, whose emission spectrum peaks at a wavelength of 610 nm. The electroluminescent transients in the current density range, 4 mA/cm(2)triplet density dynamics. Our analysis shows that triplets positively contribute to the OLED efficiency at J<2.2 A/cm(2), while decreasing the efficiency at higher J. The high OLED peak external quantum efficiency of 6.7% and rapid efficiency roll-off with J are quantitatively explained by the tradeoff between triplet-triplet and singlet-triplet annihilation. The model suggests optimal materials properties needed for achieving high efficiency at high brightness in fluorescent OLEDs. PMID:23005014

  20. Clarifying the mechanism of triplet-triplet annihilation in phosphorescent organic host-guest systems: A combined experimental and simulation study

    Science.gov (United States)

    Zhang, L.; van Eersel, H.; Bobbert, P. A.; Coehoorn, R.

    2016-05-01

    At high brightness, triplet-triplet annihilation (TTA) reduces the efficiency of organic light-emitting diodes. Triplet diffusion may considerably enhance this effect, which is otherwise limited by the rate of long-range interactions. Although its role can be clarified by studying the emissive dye concentration dependence of the TTA loss, we demonstrate here the practical applicability of a more direct method, requiring a study for only a single dye concentration. The method uses transient photoluminescence yield measurements, for a wide initial excitation density range. The analysis is applied to an iridium complex and is supported by the results of kinetic Monte Carlo simulations.

  1. Laser-induced atomic fragment fluorescence spectroscopy: a facile technique for molecular spectroscopy of spin-forbidden states.

    Science.gov (United States)

    Zhang, Qun; Chen, Yang; Keil, Mark

    2009-03-01

    Spectra of spin-forbidden and spin-allowed transitions in the mixed b (3)Pi(u) approximately A (1)Sigma(u)(+) state of Na(2) are measured separately by two-photon excitation using a single tunable dye laser. The two-photon excitation produces Na(*)(3p) by photodissociation, which is easily and sensitively detected by atomic fluorescence. At low laser power, only the A (1)Sigma(u)(+) state is excited, completely free of triplet excitation. At high laser power, photodissociation via the intermediate b (3)Pi(u) triplet state becomes much more likely, effectively "switching" the observations from singlet spectroscopy to triplet spectroscopy with only minor apparatus changes. This technique of perturbation-assisted laser-induced atomic fragment fluorescence may therefore be especially useful as a general vehicle for investigating perturbation-related physics pertinent to the spin-forbidden states, as well as for studying allowed and forbidden states of other molecules.

  2. Efficient Design of Triplet Based Spike-Timing Dependent Plasticity

    CERN Document Server

    Azghadi, Mostafa Rahimi; Iannella, Nicolangelo; Abbott, Derek

    2012-01-01

    Spike-Timing Dependent Plasticity (STDP) is believed to play an important role in learning and the formation of computational function in the brain. The classical model of STDP which considers the timing between pairs of pre-synaptic and post-synaptic spikes (p-STDP) is incapable of reproducing synaptic weight changes similar to those seen in biological experiments which investigate the effect of either higher order spike trains (e.g. triplet and quadruplet of spikes), or, simultaneous effect of the rate and timing of spike pairs on synaptic plasticity. In this paper, we firstly investigate synaptic weight changes using a p-STDP circuit and show how it fails to reproduce the mentioned complex biological experiments. We then present a new STDP VLSI circuit which acts based on the timing among triplets of spikes (t-STDP) that is able to reproduce all the mentioned experimental results. We believe that our new STDP VLSI circuit improves upon previous circuits, whose learning capacity exceeds current designs due ...

  3. Mode of conception of triplets and high order multiple pregnancies.

    LENUS (Irish Health Repository)

    Basit, I

    2012-03-01

    A retrospective audit was performed of all high order multiple pregnancies (HOMPs) delivered in three maternity hospitals in Dublin between 1999 and 2008. The mode of conception for each pregnancy was established with a view to determining means of reducing their incidence. A total of 101 HOMPs occurred, 93 triplet, 7 quadruplet and 1 quintuplet. Information regarding the mode of conception was available for 78 (81%) pregnancies. Twenty eight (27.7%) were spontaneous, 34 (33.7%) followedlVF\\/ICSI\\/FET treatment (in-vitro fertilisation, intracytoplasmic sperm injection, frozen embryo transfer), 16 (15.8%) resulted from Clomiphene Citrate treatment and 6 (6%) followed ovulation induction with gonadotrophins. Triplet and HOMPs are a major cause of maternal, feta land neonatal morbidity. Many are iatrogenic, arising from fertility treatments including Clomiphene. Reducing the numbers of embryos transferred will address IVF\\/ICSI\\/FET-related multiple pregnancy rates and this is currently happening in Ireland. Clomiphene and gonadotrophins should only be prescribed when appropriate resources are available to monitor patients adequately.

  4. The Calcium Triplet metallicity calibration for galactic bulge stars

    CERN Document Server

    Vasquez, S; Hill, V; Gonzalez, O A; Saviane, I; Rejkuba, M; Battaglia, G

    2015-01-01

    We present a new calibration of the Calcium II Triplet equivalent widths versus [Fe/H], constructed upon K giant stars in the Galactic bulge. This calibration will be used to derive iron abundances for the targets of the GIBS survey, and in general it is especially suited for solar and supersolar metallicity giants, typical of external massive galaxies. About 150 bulge K giants were observed with the GIRAFFE spectrograph at VLT, both at resolution R~20,000 and at R~6,000. In the first case, the spectra allowed us to perform direct determination of Fe abundances from several unblended Fe lines, deriving what we call here high resolution [Fe/H] measurements. The low resolution spectra allowed us to measure equivalent widths of the two strongest lines of the near infrared Calcium II triplet at 8542 and 8662 A. By comparing the two measurements we derived a relation between Calcium equivalent widths and [Fe/H] that is linear over the metallicity range probed here, -1<[Fe/H]<+0.7. By adding a small second or...

  5. Caught in the Act: Discovery of a Physical Quasar Triplet

    CERN Document Server

    Farina, E P; Decarli, R; Fumagalli, M

    2013-01-01

    We present the discovery of a triplet of quasars at z~1.51. The whole system is well accommodated within 25 arcsec (i.e., 200 kpc in projected distance). The velocity differences among the three objects (as measured through the broad MgII emission line) are less than 1000 km/s, suggesting that the quasars belong to the same physical structure. Broad band NIR images of the field do not reveal evidence of galaxies or galaxy clusters that could act as a gravitational lens, ruling out the possibility that two or all the three quasars are multiple images of a single, strongly lensed source. QQQ J1519+0627 is the second triplet of quasars known up to date. We estimate that these systems are extremely rare in terms of simple accidental superposition. The lack of strong galaxy overdensity suggests that this peculiar system is harboured in the seeds of a yet-to-be-formed massive structure. Based on observations collected at the La Silla Observatory with the New Technology Telescope (NTT) of the European Southern Obser...

  6. Synthesis, spectroscopic and thermal studies of Mg(II), Ca(II), Sr(II) and Ba(II) diclofenac sodium complexes as anti-inflammatory drug and their protective effects on renal functions impairment and oxidative stress

    Science.gov (United States)

    El-Megharbel, Samy M.; Hamza, Reham Z.; Refat, Moamen S.

    2015-01-01

    The main task of our present study is the preparation of newly complexes of Mg(II), Ca(II), Sr(II) and Ba(II) with diclofenac which succeeded to great extent in alleviating the side effects of diclofenac alone and ameliorating the kidney function parameters and antioxidant capacities with respect to diclofenac treated group alone. The Mg(II), Ca(II), Sr(II) and Ba(II) with diclofenac have been synthesized and characterized using infrared, electronic and 1H NMR spectral, thermogravimetric and conductivity measurements. The diclofenac ligand has been found to act as bidentate chelating agent. Diclofenac complexes coordinate through the oxygen's of the carboxyl group. The molar ratio chelation is 1:2 (M2+-dic) with general formula [M(dic)2(H2O)2]ṡnH2O. Antibacterial screening of the alkaline earth metal complexes against Escherichia coli (Gram - ve), Bacillus subtilis (Gram + ve) and anti-fungal (Asperagillus oryzae, Asperagillus niger, Asperagillus flavus) were investigated. The kidney functions in male albino rats were ameliorated upon treatment with metal complexes of dic, which are represented by decreasing the levels of urea and uric acid to be located within normal values. The other looks bright spot in this article is the assessment of antioxidant defense system including SOD, CAT and MDA with the help of Sr2+, Mg2+ and Ca2+-dic complexes. The hormones related to kidney functions and stresses have been greatly ameliorated in groups treated with dic complexes in comparable with dic treated group.

  7. Using the Ca II Triplet to Trace Abundance Variations in Individual Red Giant Branch stars in Three Nearby Galaxies

    CERN Document Server

    Tolstoy, E; Cole, A A; Pasquini, L; Gilmozzi, R; Gallagher, J S; Tolstoy, Eline; Irwin, Michael J.; Cole, Andrew A.

    2001-01-01

    Spectroscopic abundance determinations for stars spanning a Hubble time in age are necessary in order to unambiguously determine the evolutionary histories of galaxies. Using FORS1 in Multi-Object Spectroscopy mode on ANTU (UT1) at the ESO-VLT on Paranal we obtained near infrared spectra from which we measured the equivalent widths of the two strongest Ca II triplet lines to determine metal abundances for a sample of Red Giant Branch stars, selected from ESO-NTT optical (I, V-I) photometry of three nearby, Local Group, galaxies: the Sculptor Dwarf Spheroidal, the Fornax Dwarf Spheroidal and the Dwarf Irregular NGC 6822. The summed equivalent width of the two strongest lines in the Ca II triplet absorption line feature, centered at 8500A, can be readily converted into an [Fe/H] abundance using the previously established calibrations by Armandroff & Da Costa (1991) and Rutledge, Hesser & Stetson (1997). We measured metallicities for 37 stars in Sculptor, 32 stars in Fornax, and 23 stars in NGC 6822, yie...

  8. Triplet-triplet annihilation upconversion in CdS-decorated SiO2 nanocapsules for sub-bandgap photocatalysis.

    Science.gov (United States)

    Kwon, Oh Seok; Kim, Jae-Hyuk; Cho, Jin Ku; Kim, Jae-Hong

    2015-01-14

    This study reports the first successful nanoscale encapsulation of triplet-triplet annihilation upconversion (TTA-UC) medium within a rigid silica shell using a self-assembly microemulsion process. These newly synthesized nanocapsules present a few critical advances that could be instrumental for a wide range of aqueous-based photonics applications, including photocatalysis, artificial photosynthesis, and bioimaging. The nanocapsules form a homogeneous suspension that can produce intense, diffuse UC emission in water without deoxygenation, closely resembling conventional TTA-UC processes that have been performed in deoxygenated organic solvents. The silica shell provides sites for further surface modification, which allows, when combined with its nanoscale dimension and structural rigidity, this TTA-UC system to acquire various useful functionalities. A benchmark TTA-UC pair, palladium(II) tetraphenyltetrabenzoporphyrin as a sensitizer and perylene as an acceptor, was used to demonstrate efficient red-to-blue (635 nm, 1.95 eV → 470 nm, 2.6 eV) upconversion in the oxygen-rich aqueous phase. The nanocapsule surface was further functionalized with cadmium sulfide nanoparticles (Eg = 2.4 eV) to demonstrate sub-bandgap sensitization and subsequent aqueous-phase catalytic oxidation.

  9. A new algorithm for predicting triplet-triplet energy-transfer activated complex coordinate in terms of accurate potential-energy surfaces

    Science.gov (United States)

    Frutos, Luis Manuel; Castaño, Obis

    2005-09-01

    The new algorithm presented here allows, for the first time, the determination of the optimal geometrical distortions that an acceptor molecule in the triplet-triplet energy-transfer process undergoes, as well as the dependence of the activation energy of the process on the triplet energy difference of donor and acceptor molecules. This algorithm makes use of the complete potential-energy surfaces (singlet and triplet states), and contrasts with the first-order approximation already published [L. M. Frutos, O. Castaño, J. L. Andrés, M. Merchán, and A. U. Acuña, J. Chem. Phys. 120, 1208 (2004)] in which an expansion of the potential-energy surfaces was used. This algorithm is gradient based and finds the best trajectory for the acceptor molecule, starting from S0 ground-state equilibrium geometry, to achieve the maximum variation of the singlet-triplet energy gap with the minimum energy of activation on S0. Therefore, the algorithm allows the determination of a "reaction path" for the triplet-triplet energy-transfer processes. Also, the algorithm could also serve eventually to find minimum-energy crossing (singlet-triplet) points on the potential-energy surface, which can play an important role in the intersystem crossing process for the acceptor molecules to recover their initial capacity as acceptors. Also addressed is the misleading use of minimum-energy paths in T1 to describe the energy-transfer process by comparing these results with those obtained using the new algorithm. The implementation of the algorithm is illustrated with different potential-energy surface models and it is discussed in the frame of nonvertical behavior.

  10. Spectroscopic evidence for triplet excitation energy transfer among carotenoids in the LH2 complex from photosynthetic bacterium Rhodopseudomonas palustris

    Institute of Scientific and Technical Information of China (English)

    FENG Juan; WANG Qian; ZHANG Xujia; HUANG Youguo; AI Xicheng; ZHANG Xingkang; ZHANG Jianping

    2004-01-01

    The LH2 complex from Rhodopsudomonas (Rps.) palustris is unique in the heterogeneous carotenoid compositions. The dynamics of triplet excited state Carotenoids (3Car*) has been investigated by means of sub-microsecond time-resolved absorption spectroscopy both at physiological temperature (295 K) and at cryogenic temperature (77 K). Broad and asymmetric Tn←T1 transient absorption was observed at room temperature following the photo-excitation of Car at 532 nm, which suggests the contribution from various carotenoid compositions having different numbers of conjugated C=C double bonds (NC=C). The triplet absorption bands of different carotenoids, which superimposed at room temperature, could be clearly distinguished upon decreasing the temperature down to 77 K. At room temperature the shorter-wavelength side of the main Tn←T1 absorption band decayed rapidly to reach a spectral equilibration with a characteristic time constant of~1 μs, the same spectral dynamics, however, was not observed at 77 K. The aforementioned spectral dynamics can be explained in terms of the triplet-excitation transfer among heterogeneous carotenoid compositions. Global spectral analysis was applied to the time-resolved spectra at room temperature, which revealed two spectral components peaked at 545 and 565 nm, and assignable to the Tn←T1 absorption of Cars with NC=C=11 and NC=C=13, respectively. Surprisingly, the decay time constant of a shorter-con- jugated Car, I.e. 0.72 μs (aerobic) and 1.36 μs (anaerobic), is smaller than that of a longer-con- jugated Car, I.e. 2.12 μs (aerobic) and 3.75 μs (anaerobic), which is contradictory to the general rule of carotenoids and relative polyenes. The results are explained in terms of triplet-excitation transfer among different types of Cars. It is postulated that two Cars with different conjugation lengths coexist in an α,β-subunit in the LH2 complex.

  11. Quenching of the triplet state of benzophenone by lanthanide 1,3-diketonate chelates in solutions

    International Nuclear Information System (INIS)

    The phosphorescence of benzophenone in benzene and acetonitrile was quenched by several lanthanide (Sm, Eu, Gd, Tb and Dy) acetylacetonate chelates. The results of Stern-Volmer analysis including the quenching of benzophenone triplet and sensitization of lanthanide emission indicate that the quenching process occurs by the energy transfer mechanism via the excited triplet state of the ligand. (Author)

  12. Resonance raman and absorption spectra of isomeric retinals in their lowest excited triplet states

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N.-H.; Houee-Levin, C.

    1985-01-01

    implications about the size of the energy barriers separating the various triplet species are discussed. The resonance Raman spectra obtained by using either anthracene (ET = 177.7 kJ mol-1) or naphthalene (ET = 254.8 kJ mol-1) as sensitizers were virtually identical for the corresponding triplet states from...

  13. GAA triplet-repeats cause nucleosome depletion in the human genome.

    Science.gov (United States)

    Zhao, Hongyu; Xing, Yongqiang; Liu, Guoqing; Chen, Ping; Zhao, Xiujuan; Li, Guohong; Cai, Lu

    2015-08-01

    Although there have been many investigations into how trinucleotide repeats affect nucleosome formation and local chromatin structure, the nucleosome positioning of GAA triplet-repeats in the human genome has remained elusive. In this work, the nucleosome occupancy around GAA triplet-repeats across the human genome was computed statistically. The results showed a nucleosome-depleted region in the vicinity of GAA triplet-repeats in activated and resting CD4(+) T cells. Furthermore, the A-tract was frequently adjacent to the upstream region of GAA triplet-repeats and could enhance the depletion surrounding GAA triplet-repeats. In vitro chromatin reconstitution assays with GAA-containing plasmids also demonstrated that the inserted GAA triplet-repeats destabilized the ability of recombinant plasmids to assemble nucleosomes. Our results suggested that GAA triplet-repeats have lower affinity to histones and can change local nucleosome positioning. These findings may be helpful for understanding the mechanism of Friedreich's ataxia, which is associated with GAA triplet-repeats at the chromatin level.

  14. Two Birds with One Stone: Tailoring Singlet Fission for Both Triplet Yield and Exciton Diffusion Length

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Tong; Wan, Yan; Guo, Zhi; Johnson, Justin; Huang, Libai

    2016-09-14

    By direct imaging of singlet and triplet populations with ultrafast microscopy, it is shown that the triplet diffusion length and singlet fission yield can be simultaneously optimized for tetracene and its derivatives, making them ideal structures for application in bilayer solar cells.

  15. Defect density dependent photoluminescence yield and triplet diffusion length in rubrene

    Science.gov (United States)

    Irkhin, Pavel; Biaggio, Ivan; Zimmerling, Tino; Döbeli, Max; Batlogg, Bertram

    2016-02-01

    We investigate how excitonic processes in rubrene single crystals are affected by a deliberately implanted defect gradient induced by proton irradiation. Spatially resolved measurements show a gradually reduced photoluminescence quantum yield and triplet exciton diffusion length along the defect gradient. Both effects are caused by a decrease in the average triplet lifetime due to interaction with the implanted defects. The triplet lifetime was reduced by almost two orders of magnitude at the highest implanted defect density of 1017 cm-3. The strong sensitivity of the photoluminescence quantum yield to the defect density that is observed already at moderate excitation densities is caused by the combination of two effects: the dominant contribution of triplet-fusion to the observed photoluminescence and the long-range diffusion of triplet excitons.

  16. Model for Triplet State Engineering in Organic Light Emitting Diodes

    CERN Document Server

    Prodhan, Suryoday; Ramasesha, S

    2014-01-01

    Engineering the position of the lowest triplet state (T1) relative to the first excited singlet state (S1) is of great importance in improving the efficiencies of organic light emitting diodes and organic photovoltaic cells. We have carried out model exact calculations of substituted polyene chains to understand the factors that affect the energy gap between S1 and T1. The factors studied are backbone dimerisation, different donor-acceptor substitutions and twisted geometry. The largest system studied is an eighteen carbon polyene which spans a Hilbert space of about 991 million. We show that for reverse intersystem crossing (RISC) process, the best system involves substituting all carbon sites on one half of the polyene with donors and the other half with acceptors.

  17. Peripartum cardiomyopathy: a case of patient with triplet pregnancy.

    Science.gov (United States)

    Kotlica, B Kastratović; Cetković, A; Plesinac, S; Macut, D; Asanin, M

    2016-01-01

    Peripartum cardiomyopathy (PPCM) is a rare but potentially devastating complication of pregnancy associated with heart failure due to left ventricular systolic dysfunction occurring within the last month of pregnancy and five month postpartum with no obvious other cause of heart failure and no pre-existing heart disease. In the present case report the authors present a woman who developed PPCM on the day after she delivered by cesarean section in 35th weeks of gestation of triplet pregnancy conceived after ovarian stimulation and insemination. A treatment with diuretics, ACE inhibitors, antiarrhythmics, low weight heparin, antibiotics and bromocriptine was applied and resulted in complete recovery. In conclusion, timely detection and initiation of treatment are important factors for complete recovery of patients with PPCM. PMID:27132428

  18. Manufacturing experience for the LHC inner triplet quadrupole cables

    Energy Technology Data Exchange (ETDEWEB)

    Scanlan, R.M.; Higley, H.C.; Bossert, R.; Kerby, J.; Gosh, A.K.; Boivin, M.; Roy, T.

    2001-06-12

    The design for the U.S. LHC Inner Triplet Quadrupole magnet requires a 37 strand (inner layer) and a 46 strand (outer layer) cable. This represents the largest number of strands attempted to date for a production quantity of Rutherford-type cable. The cable parameters were optimized during the production of a series of short prototype magnets produced at FNAL. These optimization studies focused on critical current degradation, dimensional control, coil winding, and interstrand resistance. After the R&D phase was complete, the technology was transferred to NEEW and a new cabling machine was installed to produce these cables. At present, about 60 unit lengths, out of 90 required for the entire production series of magnets, have been completed for each type of cable. The manufacturing experience with these challenging cables will be reported. Finally, the implications for even larger cables, with more strands, will be discussed.

  19. Manufacturing experience for the LHC inner triplet quadrupole cables

    CERN Document Server

    Scanlan, R M; Bossert, R; Kerby, J S; Ghosh, A K; Boivin, M; Roy, T

    2002-01-01

    The design for the U.S. LHC Inner Triplet Quadrupole magnet requires a 37 strand (inner layer) and a 46 strand (outer layer) cable. This represents the largest number of strands attempted to date for a production quantity of Rutherford-type cable. The cable parameters were optimized during the production of a series of short prototype magnets produced at FNAL. These optimization studies focused on critical current degradation, dimensional control, coil winding, and interstrand resistance. After the R&D phase was complete, the technology was transferred to NEEW and a new cabling machine was installed to produce these cables. At present, about 60 unit lengths, out of 90 required for the entire production series of magnets, have been completed for each type of cable. The manufacturing experience with these challenging cables will be reported. Finally, the implications for even larger cables, with more strands, will be discussed. (8 refs).

  20. Observation of rogue wave triplets in water waves

    Energy Technology Data Exchange (ETDEWEB)

    Chabchoub, A., E-mail: achabchoub@swin.edu.au [Centre for Ocean Engineering Science and Technology, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia); Department of Mechanical Engineering, Imperial College London, London SW7 2AZ (United Kingdom); Akhmediev, N. [Optical Sciences Group, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)

    2013-11-15

    Doubly-localised breather solutions of the nonlinear Schrödinger equation (NLS) are considered to be appropriate models to describe rogue waves in water waves as well as in other nonlinear dispersive media such as fibre optics. Within the hierarchy of this type of formations, the Peregrine breather (PB) is the lowest-order rational solution. Higher-order solutions of this kind may be understood as a nonlinear superposition of fundamental Peregrine solutions. These superpositions are nontrivial and admit only a fixed well prescribed number of elementary breathers in each higher-order solution. Here, we report first observation of second-order solution which in reality is a triplet of rogue waves.

  1. Mother-daughter in vitro fertilization triplet surrogate pregnancy.

    Science.gov (United States)

    Michelow, M C; Bernstein, J; Jacobson, M J; McLoughlin, J L; Rubenstein, D; Hacking, A I; Preddy, S; Van der Wat, I J

    1988-02-01

    A successful triplet pregnancy has been established in a surrogate gestational mother following the transfer of five embryos fertilized in vitro. The oocytes were donated by her biological daughter, and the sperm obtained from the daughter's husband. The daughter's infertility followed a total abdominal hysterectomy performed for a postpartum hemorrhage as a result of a placenta accreta. Synchronization of both their menstrual cycles was obtained using oral contraceptive suppression for 2 months, followed by stimulation of both the surrogate gestational mother and her daughter such that embryo transfer would occur at least 48 hr after the surrogate gestational mother's own ovulation. This case raises a number of medical, social, psychological, and ethical issues. PMID:3367072

  2. Multi-Lepton Signatures of the Triplet Like Charged Higgs at the LHC

    CERN Document Server

    Bandyopadhyay, Priyotosh; Keceli, Asli Sabanci

    2014-01-01

    We study multi-lepton signatures of the triplet like charged Higgs at the LHC in the context of $Y=0$ triplet extended supersymmetric model (TESSM). In TESSM the $h_i^\\pm W^\\mp Z$ coupling appears at tree level when the triplet vacuum expectation value is nonzero, and because of the coupling the charged Higgs decay channels as well as the production channels can dramatically change at the LHC. We show that for the triplet dominated charged Higgs the main production channels are no longer through the top decay or $gg$ and $gb$ fusions since these are very suppressed due to the lack of triplet-SM fermion coupling. In the numerical analysis, we consider also other possible production channels some of which have additional contributions from the diagrams containing $h_i^\\pm W^\\mp Z$ vertex. We investigate the decay channels of a triplet like light charged Higgs ($m_{h_1^{\\pm}}\\leq 200$ GeV) and show that depending on the triplet component, the charged Higgs can substantially decay to $W^\\pm Z$. We further examine...

  3. Orbifold Grand Unification: A Solution to the Doublet-Triplet Problem

    CERN Document Server

    Jia, Bei

    2014-01-01

    To solve the doublet-triplet splitting problem in SU(5) grand unified theories, we propose a four dimensional orbifold grand unified theory by acting Z2 on the SU(5) gauge group. Without an adjoint Higgs, the orbifold procedure breaks the SU(5) gauge symmetry down to the standard model gauge group, and removes the triplet component of the fundamental SU(5) Higgs. In the supersymmetric framework, we show that the orbifold procedure removes two triplet superfields of the Higgs multiplets and leaves us with the minimal supersymmetric standard model, which also solves the hierarchy problem and realizes gauge coupling unification. We also discuss possible UV completions of the orbifold theories.

  4. Formation of the O I resonance triplet and intercombination doublet in the solar chromosphere

    Science.gov (United States)

    Skelton, D. L.; Shine, R. A.

    1982-01-01

    Spectrum synthesis calculations are presented for the O I resonance triplet at 1304 A and the intercombination doublet at 1358 A for the solar atmosphere and several variants, allowing for triplet fluorescence by the Ly-beta emission of H I. Profiles, synthesized from a seven-level plus continuum O I atom are compared to observations taken with the high-resolution spectrometer on OSO 8. It is found that the O I triplet emission is dominated by the Ly-beta fluorescence and that the agreement between observations and profiles computed with current chromospheric models is much improved over earlier studies.

  5. Isolation of proximity-induced triplet pairing channel in a superconductor/ferromagnet spin valve

    OpenAIRE

    Leksin, P. V.; Garifyanov, N. N.; Kamashev, A. A.; Validov, A. A.; Fominov, Ya. V.; Schumann, J.; KATAEV V.; J. Thomas; Büchner, B.; Garifullin, I. A.

    2015-01-01

    We have studied the proximity-induced superconducting triplet pairing in CoO$_x$/Py1/Cu/Py2/Cu/Pb spin-valve structure (where Py = Ni$_{0.81}$Fe$_{0.19}$). By optimizing the parameters of this structure we found a triplet channel assisted full switching between the normal and superconducting states. To observe an "isolated" triplet spin-valve effect we exploited the oscillatory feature of the magnitude of the ordinary spin-valve effect $\\Delta T_c$ in the dependence of the Py2-layer thickness...

  6. Comparison of the superconducting proximity effect in the superconductors with singlet, OSP and ESP triplet pairings

    Directory of Open Access Journals (Sweden)

    M Araie

    2013-10-01

    Full Text Available In this paper, we investigate the superconducting proximity effect for a superconductor with three types of singlet, OSP and ESP triplet pairings in contact with a clean ferromagnetic region. Using the quasiclassical Green’s function approach, we calculate the superconducting pair amplitude function in terms of the characteristic parameters of the system and compare penetration of these superconducting correlations inside the ferromagnetic region. We show that the ESP triplet correlations have a long range thermal penetration compared with the singlet and OSP triplet correlations inside the ferromagnetic region.

  7. Efficient photon triplet generation in integrated nanophotonic waveguides.

    Science.gov (United States)

    Moebius, Michael G; Herrera, Felipe; Griesse-Nascimento, Sarah; Reshef, Orad; Evans, Christopher C; Guerreschi, Gian Giacomo; Aspuru-Guzik, Alán; Mazur, Eric

    2016-05-01

    Generation of entangled photons in nonlinear media constitutes a basic building block of modern photonic quantum technology. Current optical materials are severely limited in their ability to produce three or more entangled photons in a single event due to weak nonlinearities and challenges achieving phase-matching. We use integrated nanophotonics to enhance nonlinear interactions and develop protocols to design multimode waveguides that enable sustained phase-matching for third-order spontaneous parametric down-conversion (TOSPDC). We predict a generation efficiency of 0.13 triplets/s/mW of pump power in TiO2-based integrated waveguides, an order of magnitude higher than previous theoretical and experimental demonstrations. We experimentally verify our device design methods in TiO2 waveguides using third-harmonic generation (THG), the reverse process of TOSPDC that is subject to the same phase-matching constraints. We finally discuss the effect of finite detector bandwidth and photon losses on the energy-time coherence properties of the expected TOSPDC source. PMID:27137604

  8. Vortex lines in a ferromagnetic spin-triplet superconductor

    Institute of Scientific and Technical Information of China (English)

    Zhao Li; Yang Jie; Xie Qun-Ying; Tian Miao; Duan Yi-Shi

    2012-01-01

    Based on Duan's topological current theory,we show that in a ferromagnetic spin-triplet superconductor there is a topological defect of string structures which can be interpreted as vortex lines.Such defects are different from the Abrikosov vortices in one-component condensate systems.We investigate the inner topological structure of the vortex lines.The topological charge density,velocity,and topological current of the vortex lines can all be expressed in terms of δ function,which indicates that the vortices can only arise from the zero points of an order parameter field.The topological charges of vortex lines are quantized in terms of the Hopf indices and Brouwer degrees of φ-mapping.The divergence of the self-induced magnetic field can be rigorously determined by the corresponding order parameter fields and its expression also takes the form of a δ-like function.Finally,based on the implicit function theorem and the Taylor expansion,we conduct detailed studies on the bifurcation of vortex topological current and find different directions of the bifurcation.

  9. An atlas of Calcium triplet spectra of active galaxies

    CERN Document Server

    Garcia-Rissmann, A; Asari, N V; Fernandes, R C; Schmitt, H; González-Delgado, R M; Storchi-Bergmann, T

    2005-01-01

    We present a spectroscopic atlas of active galactic nuclei covering the region around the 8498, 8542, 8662 Calcium triplet (CaT) lines. The sample comprises 78 objects, divided into 43 Seyfert 2s, 26 Seyfert 1s, 3 Starburst and 6 normal galaxies. The spectra pertain to the inner ~300 pc in radius, and thus sample the central kinematics and stellar populations of active galaxies. The data are used to measure stellar velocity dispersions (sigma_star) both with cross-correlation and direct fitting methods. These measurements are found to be in good agreement with each-other and with those in previous studies for objects in common. The CaT equivalent width is also measured. We find average values and sample dispersions of W_CaT of 4.6+/-2.0, 7.0 and 7.7+/-1.0 angstrons for Seyfert 1s, Seyfert 2s and normal galaxies, respectively. We further present an atlas of [SIII]\\lambda 9069 emission line profiles for a subset of 40 galaxies. These data are analyzed in a companion paper which addresses the connection between ...

  10. The 3-3-1 model with inert scalar triplet

    CERN Document Server

    Dong, P V; Soa, D V

    2013-01-01

    We show that the typical 3-3-1 models are only self-consistent if they contain interactions explicitly violating the lepton number. The 3-3-1 model with right-handed neutrinos can by itself work as an economical 3-3-1 model as a natural recognition of the above criteria while it also results an inert scalar triplet (\\eta) responsible for dark matter. This is ensured by a Z_2 symmetry (assigned so that only \\eta is odd while all other multiplets which perform the economical 3-3-1 model are even), which is not broken by the vacuum. The dark matter candidate (H_\\eta) contained in \\eta transforms as a singlet under the standard model symmetry and being naturally heavy. The H_\\eta relic density and direct detection cross-section will get right values when the H_\\eta mass is in TeV range as expected. The model predicts the H_\\eta mass m_{H_\\eta}=\\la_5 \\times 2 TeV and the H_\\eta-nucleon scattering cross-section \\sigma_{H_\\eta-N}=1.56 \\times 10^{-44} cm^2, provided that the new neutral Higgs boson is heavy enough th...

  11. Noise filtering of composite pulses for singlet-triplet qubits.

    Science.gov (United States)

    Yang, Xu-Chen; Wang, Xin

    2016-01-01

    Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors and are therefore of great interest both theoretically and experimentally. They are, however, designed under the static-noise model and may be considered as low-frequency filters. In this work, we perform a comprehensive theoretical study of the response of a type of dynamically corrected gates, namely the supcode for singlet-triplet qubits, to realistic 1/f noises with frequency spectra 1/ω(α). Through randomized benchmarking, we have found that supcode offers improvement of the gate fidelity for α  1 and the improvement becomes exponentially more pronounced with the increase of the noise exponent in the range 1  α ≤ 3 studied. On the other hand, for small α, supcode will not offer any improvement. The δJ-supcode, specifically designed for systems where the nuclear noise is absent, is found to offer additional error reduction than the full supcode for charge noises. The computed filter transfer functions of the supcode gates are also presented. PMID:27383129

  12. Radiative corrections to the Higgs couplings in the triplet model

    CERN Document Server

    Kikuchi, Mariko

    2013-01-01

    The feature of extended Higgs models can appear in the pattern of deviations from the Standard Model (SM) predictions in coupling constants of the SM-like Higgs boson ($h$). We can thus discriminate extended Higgs models by precisely measuring the pattern of deviations in the coupling constants of $h$, even when extra bosons are not found directly. In order to compare the theoretical predictions to the future precision data at the ILC, we must evaluate the theoretical predictions with radiative corrections in various extended Higgs models. In this talk, we give our comprehensive study for radiative corrections to various Higgs boson couplings of $h$ in the minimal Higgs triplet model (HTM). First, we define renormalization conditions in the model, and we calculate the Higgs coupling; $g\\gamma\\gamma, hWW, hZZ$ and $hhh$ at the one loop level. We then evaluate deviations in coupling constants of the SM-like Higgs boson from the predictions in the SM. We find that one-loop contributions to these couplings are su...

  13. Noise filtering of composite pulses for singlet-triplet qubits

    Science.gov (United States)

    Yang, Xu-Chen; Wang, Xin

    2016-01-01

    Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors and are therefore of great interest both theoretically and experimentally. They are, however, designed under the static-noise model and may be considered as low-frequency filters. In this work, we perform a comprehensive theoretical study of the response of a type of dynamically corrected gates, namely the supcode for singlet-triplet qubits, to realistic 1/f noises with frequency spectra 1/ωα. Through randomized benchmarking, we have found that supcode offers improvement of the gate fidelity for α  1 and the improvement becomes exponentially more pronounced with the increase of the noise exponent in the range 1  α ≤ 3 studied. On the other hand, for small α, supcode will not offer any improvement. The δJ-supcode, specifically designed for systems where the nuclear noise is absent, is found to offer additional error reduction than the full supcode for charge noises. The computed filter transfer functions of the supcode gates are also presented. PMID:27383129

  14. Noise filtering of composite pulses for singlet-triplet qubits

    Science.gov (United States)

    Yang, Xu-Chen; Wang, Xin

    2016-07-01

    Semiconductor quantum dot spin qubits are promising candidates for quantum computing. In these systems, the dynamically corrected gates offer considerable reduction of gate errors and are therefore of great interest both theoretically and experimentally. They are, however, designed under the static-noise model and may be considered as low-frequency filters. In this work, we perform a comprehensive theoretical study of the response of a type of dynamically corrected gates, namely the SUPCODE for singlet-triplet qubits, to realistic 1/f noises with frequency spectra 1/ωα. Through randomized benchmarking, we have found that SUPCODE offers improvement of the gate fidelity for α  1 and the improvement becomes exponentially more pronounced with the increase of the noise exponent in the range 1  α ≤ 3 studied. On the other hand, for small α, SUPCODE will not offer any improvement. The δJ-SUPCODE, specifically designed for systems where the nuclear noise is absent, is found to offer additional error reduction than the full SUPCODE for charge noises. The computed filter transfer functions of the supcode gates are also presented.

  15. Hadronic production of light color-triplet Higgs bosons: An alternative signature for grand unified theories

    International Nuclear Information System (INIS)

    The conventional signature for grand unified theories (GUTs) is proton decay. Recently, some models in extra dimensions or with specific discrete symmetries, which aim at solving the doublet-triplet problem, allow a color triplet in the TeV mass region by suppressing the Yukawa couplings of the triplets to matter fermions. We study the hadronic production and detection of these TeV colored Higgs bosons as an alternative signature for GUTs; they would behave like massive stable charged particles in particle detectors, producing the striking signature of a charged track in the central tracking system and being ionized in the outer muon chamber. We find that the CERN LHC is sensitive to a colored Higgs boson up to about 1.5 TeV. If the color triplets are stable on a cosmological time scale, they may constitute an interesting fraction of the dark matter

  16. The structure of strongly additive states and Markov triplets on the CAR algebra

    CERN Document Server

    Jencova, Anna

    2010-01-01

    We find a characterization of states satisfying equality in strong subadditivity of entropy and of Markov triplets on the CAR algebra. For even states, a more detailed structure of the density matrix is given.

  17. The origin of efficient triplet state population in sulfur-substituted nucleobases

    Science.gov (United States)

    Mai, Sebastian; Pollum, Marvin; Martínez-Fernández, Lara; Dunn, Nicholas; Marquetand, Philipp; Corral, Inés; Crespo-Hernández, Carlos E.; González, Leticia

    2016-10-01

    Elucidating the photophysical mechanisms in sulfur-substituted nucleobases (thiobases) is essential for designing prospective drugs for photo- and chemotherapeutic applications. Although it has long been established that the phototherapeutic activity of thiobases is intimately linked to efficient intersystem crossing into reactive triplet states, the molecular factors underlying this efficiency are poorly understood. Herein we combine femtosecond transient absorption experiments with quantum chemistry and nonadiabatic dynamics simulations to investigate 2-thiocytosine as a necessary step to unravel the electronic and structural elements that lead to ultrafast and near-unity triplet-state population in thiobases in general. We show that different parts of the potential energy surfaces are stabilized to different extents via thionation, quenching the intrinsic photostability of canonical DNA and RNA nucleobases. These findings satisfactorily explain why thiobases exhibit the fastest intersystem crossing lifetimes measured to date among bio-organic molecules and have near-unity triplet yields, whereas the triplet yields of canonical nucleobases are nearly zero.

  18. Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A

    OpenAIRE

    Leinson, Lev B.

    2014-01-01

    In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfl...

  19. Spiro-linked hyperbranched architecture in electrophosphorescent conjugated polymers for tailoring triplet energy back transfer.

    Science.gov (United States)

    Shao, Shiyang; Ma, Zhihua; Ding, Junqiao; Wang, Lixiang; Jing, Xiabin; Wang, Fosong

    2012-04-17

    A spiro-linked hyperbranched architecture has been incorporated into electrophosphorescent conjugated polymers for the first time, aiming at simultaneously tailoring the intra- and intermolecular triplet energy back transfer from the phosphorescent guest to the conjugated polymer host. Based on a prototype with this unique structure, slower decay of triplet excitons, and 5-8 fold enhancement of device efficiencies are obtained compared with the conventional blending counterpart.

  20. Sensitized Triplet Formation of Chlorophyll-A and beta-Carotene

    DEFF Research Database (Denmark)

    Jensen, Nina Mejlhede; Wilbrandt, Robert Walter; Pagsberg, Palle Bjørn

    1980-01-01

    The naphthalene-sensitized formation of triplet excited chlorophyll-a (Chl-a) and all-transß-carotene has been studied by pulse radiolysis. The rate constants for transfer of triplet energy from naphthalene to Chl-a and all-transß-carotene in benzene at 25°C are (3.6 ± 0.6)·109M-1 s-1 and (10.7 ± 1...

  1. Autler-Townes multiplet spectroscopy

    CERN Document Server

    Ghafoor, Fazal

    2013-01-01

    We extend the concepts of the Autler-Townes doublet and triplet spectroscopy to quartuplet, quintuplet and suggest linkages in sodium atom in which to display these spectra. We explore the involved fundamental processes of quantum interference of the corresponding spectroscopy by examining the Laplace transform of the corresponding state-vector subjected to steady coherent illumination in the rotating wave approximation and Weisskopf-Wigner treatment of spontaneous emission as a simplest probability loss. In the quartuplet, four fields interact appropriately and resonantly with the five-level atom. The spectral profile of the single decaying level, upon interaction with three other levels, splits into four destructively interfering dressed states generating three dark lines in the spectrum. These dark lines divide the spectrum into four spectral components (bright lines) whose widths are effectively controlled by the relative strength of the laser fields and the relative width of the single decaying level. We...

  2. The trouble with triplets in biodiversity informatics: a data-driven case against current identifier practices.

    Directory of Open Access Journals (Sweden)

    Robert Guralnick

    Full Text Available The biodiversity informatics community has discussed aspirations and approaches for assigning globally unique identifiers (GUIDs to biocollections for nearly a decade. During that time, and despite misgivings, the de facto standard identifier has become the "Darwin Core Triplet", which is a concatenation of values for institution code, collection code, and catalog number associated with biocollections material. Our aim is not to rehash the challenging discussions regarding which GUID system in theory best supports the biodiversity informatics use case of discovering and linking digital data across the Internet, but how well we can link those data together at this moment, utilizing the current identifier schemes that have already been deployed. We gathered Darwin Core Triplets from a subset of VertNet records, along with vertebrate records from GenBank and the Barcode of Life Data System, in order to determine how Darwin Core Triplets are deployed "in the wild". We asked if those triplets follow the recommended structure and whether they provide an easy and unambiguous means to track from specimen records to genetic sequence records. We show that Darwin Core Triplets are often riddled with semantic and syntactic errors when deployed and curated in practice, despite specifications about how to construct them. Our results strongly suggest that Darwin Core Triplets that have not been carefully curated are not currently serving a useful role for relinking data. We briefly consider needed next steps to overcome current limitations.

  3. The excited spin-triplet state of a charged exciton in quantum dots

    Science.gov (United States)

    Molas, M. R.; Nicolet, A. A. L.; Piętka, B.; Babiński, A.; Potemski, M.

    2016-09-01

    We report on spectroscopic studies of resonances related to ladder of states of a charged exciton in single GaAlAs/AlAs quantum dot structures. Polarization-resolved photoluminescence, photoluminescence excitation and photon-correlation measurements were performed at low (T  =  4.2 K) temperature also in magnetic field applied in Faraday configuration. The investigated resonances are assigned to three different configurations of a positively charged exciton. Together with a singlet ground state and a conventional triplet state (involving an electron from the ground state electronic s-shell), an excited triplet state, which involved an electron from the excited electronic p-shell was identified in single dots. The appearance of an emission line related to the latter complex is due to a partially suppressed electron relaxation in the investigated dots. An analysis of this emission line allows us to scrupulously determine properties of the excited triplet state and compare them with those of the conventional triplet state. Both triplets exhibit similar patterns of anisotropic fine structure and Zeeman splitting, however their amplitudes significantly differ for those two states. Presented results emphasize the role of the symmetry of the electronic state on the properties of the triplet states of two holes  +  electron excitonic complex.

  4. The excited spin-triplet state of a charged exciton in quantum dots.

    Science.gov (United States)

    Molas, M R; Nicolet, A A L; Piętka, B; Babiński, A; Potemski, M

    2016-09-14

    We report on spectroscopic studies of resonances related to ladder of states of a charged exciton in single GaAlAs/AlAs quantum dot structures. Polarization-resolved photoluminescence, photoluminescence excitation and photon-correlation measurements were performed at low (T  =  4.2 K) temperature also in magnetic field applied in Faraday configuration. The investigated resonances are assigned to three different configurations of a positively charged exciton. Together with a singlet ground state and a conventional triplet state (involving an electron from the ground state electronic s-shell), an excited triplet state, which involved an electron from the excited electronic p-shell was identified in single dots. The appearance of an emission line related to the latter complex is due to a partially suppressed electron relaxation in the investigated dots. An analysis of this emission line allows us to scrupulously determine properties of the excited triplet state and compare them with those of the conventional triplet state. Both triplets exhibit similar patterns of anisotropic fine structure and Zeeman splitting, however their amplitudes significantly differ for those two states. Presented results emphasize the role of the symmetry of the electronic state on the properties of the triplet states of two holes  +  electron excitonic complex. PMID:27391126

  5. The models of proton assisted and the unassisted formation of CGC base triplets.

    Science.gov (United States)

    Medhi, Chitrani

    2002-01-01

    The triple helix is formed by combining a double and a single strand DNAs in low pH and dissociates in high pH. Under such conditions, protonation of cytosine in the single strand is necessary for triplex formation where cytosine-guanine-cytosine (CGC+) base triplet stabilizes the triple helix. The mechanism of CGC+ triplet formation from guanine-cytosine (GC) and a protonated cytosine (C+) shows the importance of N3 proton. Similarly in the case of CGC (unprotonated) triplet, the donor acceptor H-bond at N3 hydrogen of the cytosine analog (C) initiates the interaction with GC. The correspondence between the two models of triplets, CGC+ and CGC, unambiguously assigned that protonation at N3 cytosine in low pH to be the first step in triplet formation, but a donor acceptor triplet (CGC) can be designed without involving a proton in the Hoogsteen H-bond. Further, the bases of cytosine analogue also show the capability of forming Watson Crick (WC) H-bonds with guanine.

  6. π-Conjugated Organometallic Isoindigo Oligomer and Polymer Chromophores: Singlet and Triplet Excited State Dynamics and Application in Polymer Solar Cells.

    Science.gov (United States)

    Goswami, Subhadip; Gish, Melissa K; Wang, Jiliang; Winkel, Russell W; Papanikolas, John M; Schanze, Kirk S

    2015-12-01

    An isoindigo based π-conjugated oligomer and polymer that contain cyclometalated platinum(II) "auxochrome" units were subjected to photophysical characterization, and application of the polymer in bulk heterojunction polymer solar cells with PCBM acceptor was examined. The objective of the study was to explore the effect of the heavy metal centers on the excited state properties, in particular, intersystem crossing to a triplet (exciton) state, and further how this would influence the performance of the organometallic polymer in solar cells. The materials were characterized by electrochemistry, ground state absorption, emission, and picosecond-nanosecond transient absorption spectroscopy. Electrochemical measurements indicate that the cyclometalated units have a significant impact on the HOMO energy level of the chromophores, but little effect on the LUMO, which is consistent with localization of the LUMO on the isoindigo acceptor unit. Picosecond-nanosecond transient absorption spectroscopy reveals a transient with ∼100 ns lifetime that is assigned to a triplet excited state that is produced by intersystem crossing from a singlet state on a time scale of ∼130 ps. This is the first time that a triplet state has been observed for isoindigo π-conjugated chromophores. The performance of the polymer in bulk heterojunction solar cells was explored with PC61BM as an acceptor. The performance of the cells was optimum at a relatively high PCBM loading (1:6, polymer:PCBM), but the overall efficiency was relatively low with power conversion efficiency (PCE) of 0.22%. Atomic force microscopy of blend films reveals that the length scale of the phase separation decreases with increasing PCBM content, suggesting a reason for the increase in PCE with acceptor loading. Energetic considerations show that the triplet state in the polymer is too low in energy to undergo charge separation with PCBM. Further, due to the relatively low LUMO energy of the polymer, charge transfer

  7. Laser flash photolysis study on 9-phenylxanthenium tetrafluoroborate: Identification of new features due to the triplet state

    Indian Academy of Sciences (India)

    Sanghamitra Banerjee; Anunay Samanta

    2011-01-01

    Laser flash photolysis study on highly fluorescent and stable salt of 9-phenylxanthenium cation in neutral condition has been carried out for the first time. A new transient absorption band of this extensively studied system that perhaps remained buried under the fluorescence envelope and hitherto undetected has been identified and attributed to the triplet state of the system. This oxygen-insensitive triplet-triplet absorption band in the 480-600 nm range is expected to trigger new studies exploring the reactivity of the triplet state of this system, which has so far received very little attention.

  8. Dissecting galaxy triplets in the Sloan Digital Sky Survey Data Release 10: I. Stellar populations and emission line analysis

    Science.gov (United States)

    Costa-Duarte, M. V.; O'Mill, A. L.; Duplancic, F.; Sodré, L.; Lambas, D. G.

    2016-04-01

    We identify isolated galaxy triplets in a volume-limited sample from the Sloan Digital Sky Survey Data Release 10. Our final sample has 80 galaxy systems in the redshift range 0.04≤z≤0.1, brighter than Mr = -20.5 + 5log h70. Spectral synthesis results and WHAN and BPT diagnostic diagrams were employed to classify the galaxies in these systems as star-forming, active nuclei, or passive/retired. Our results suggest that the brightest galaxies drive the triplet evolution, as evidenced by the strong correlations between properties as mass assembly and mean stellar population age with triplet properties. Galaxies with intermediate luminosity or the faintest one within the triplet seem to play a secondary role. Moreover, the relation between age and stellar mass of galaxies is similar for these galaxies but different for the brightest galaxy in the system. Most of the triplet galaxies are passive or retired, according to the WHAN classification. Low mass triplets present different fractions of WHAN classes when compared to higher mass triplets. A census of WHAN class combinations shows the dominance of star-forming galaxies in low mass triplets while retired and passive galaxies prevail in high-mass systems. We argue that these results suggest that the local environment, through galaxy interactions driven by the brightest galaxy, is playing a major role in triplet evolution.

  9. Dissecting galaxy triplets in the Sloan Digital Sky Survey Data Release 10 - I. Stellar populations and emission line analysis

    Science.gov (United States)

    Costa-Duarte, M. V.; O'Mill, A. L.; Duplancic, F.; Sodré, L.; Lambas, D. G.

    2016-07-01

    We identify isolated galaxy triplets in a volume-limited sample from the Sloan Digital Sky Survey Data Release 10. Our final sample has 80 galaxy systems in the redshift range 0.04 ≤ z ≤ 0.1, brighter than Mr = -20.5 + 5 log h70. Spectral synthesis results and WHAN and BPT diagnostic diagrams were employed to classify the galaxies in these systems as star-forming, active nuclei, or passive/retired. Our results suggest that the brightest galaxies drive the triplet evolution, as evidenced by the strong correlations between properties as mass assembly and mean stellar population age with triplet properties. Galaxies with intermediate luminosity or the faintest one within the triplet seem to play a secondary role. Moreover, the relation between age and stellar mass of galaxies is similar for these galaxies but different for the brightest galaxy in the system. Most of the triplet galaxies are passive or retired, according to the WHAN classification. Low-mass triplets present different fractions of WHAN classes when compared to higher mass triplets. A census of WHAN class combinations shows the dominance of star-forming galaxies in low-mass triplets while retired and passive galaxies prevail in high-mass systems. We argue that these results suggest that the local environment, through galaxy interactions driven by the brightest galaxy, is playing a major role in triplet evolution.

  10. Matrix genetics, part 1: permutations of positions in triplets and symmetries of genetic matrices

    CERN Document Server

    Petoukhov, Sergey V

    2008-01-01

    The hidden connection between the degeneracy of the vertebrate mitochondria genetic code and the positional permutations inside genetic triplets is described. The Kronecker family of the genetic matrices is investigated, which is based on the genetic matrix [C A; U G], where C, A, U, G are the letters of the genetic alphabet. The natural system of binary numeration of genetic multiplets in the genetic matrices is proposed. The matrix [C A; U G] in the third Kronecker power is the (8*8)-matrix, which contains 64 triplets. When 64 triplets in this matrix are numbered in accordance with the natural system, the coincidence with the famous table of 64 hexagrams of the ancient Chinese book "I Ching" arises. It is significant that peculiarities of the degeneracy of the vertebrate mitochondria genetic code are reflected in the symmetrical black-and-white mosaic of this genetic (8*8)-matrix of 64 triplets. This matrix is reformed into a new mosaic matrix when internal positions in all triplets are permuted simultaneou...

  11. Preorganized Chromophores Facilitate Triplet Energy Migration, Annihilation and Upconverted Singlet Energy Collection.

    Science.gov (United States)

    Mahato, Prasenjit; Yanai, Nobuhiro; Sindoro, Melinda; Granick, Steve; Kimizuka, Nobuo

    2016-05-25

    Photon upconversion (UC) based on triplet-triplet annihilation (TTA) has the potential to enhance significantly photovoltaic and photocatalytic efficiencies by harnessing sub-bandgap photons, but the progress of this field is held back by the chemistry problem of how to preorganize multiple chromophores for efficient UC under weak solar irradiance. Recently, the first maximization of UC quantum yield at solar irradiance was achieved using fast triplet energy migration (TEM) in metal-organic frameworks (MOFs) with ordered acceptor arrays, but at the same time, a trade-off between fast TEM and high fluorescence efficiency was also found. Here, we provide a solution for this trade-off issue by developing a new strategy, triplet energy migration, annihilation and upconverted singlet energy collection (TEM-UPCON). The porous structure of acceptor-based MOF crystals allows triplet donor molecules to be accommodated without aggregation. The surface of donor-doped MOF nanocrystals is modified with highly fluorescent energy collectors through coordination bond formation. Thanks to the higher fluorescence quantum yield of surface-bound collectors than parent MOFs, the implementation of the energy collector greatly improves the total UC quantum yield. The UC quantum yield maximization behavior at ultralow excitation intensity was retained because the TTA events take place only in the MOF acceptors. The TEM-UPCON concept may be generalized to collectors with various functions and would lead to quantitative harvesting of upconverted energy, which is difficult to achieve in common molecular diffusion-based systems.

  12. Multi-triplet bound states and finite-temperature dynamics in highly frustrated quantum spin ladders

    Science.gov (United States)

    Honecker, Andreas; Mila, Frédéric; Normand, B.

    2016-09-01

    Low-dimensional quantum magnets at finite temperatures present a complex interplay of quantum and thermal fluctuation effects in a restricted phase space. While some information about dynamical response functions is available from theoretical studies of the one-triplet dispersion in unfrustrated chains and ladders, little is known about the finite-temperature dynamics of frustrated systems. Experimentally, inelastic neutron scattering studies of the highly frustrated two-dimensional material SrCu2(BO3)2 show an almost complete destruction of the one-triplet excitation band at a temperature only 1/3 of its gap energy, accompanied by strong scattering intensities for apparent multi-triplet excitations. We investigate these questions in the frustrated spin ladder and present numerical results from exact diagonalization for the dynamical structure factor as a function of temperature. We find anomalously rapid transfer of spectral weight out of the one-triplet band and into both broad and sharp spectral features at a wide range of energies, including below the zero-temperature gap of this excitation. These features are multi-triplet bound states, which develop particularly strongly near the quantum phase transition, fall to particularly low energies there, and persist all the way to infinite temperature. Our results offer valuable insight into the physics of finite-temperature spectral functions in SrCu2(BO3)2 and many other highly frustrated spin systems.

  13. Triplet State Formation in Photovoltaic Blends of DPP-Type Copolymers and PC71BM

    KAUST Repository

    Ochsmann, Julian R.

    2015-04-29

    The exciton dynamics in pristine films of two structurally related low-bandgap diketopyrrolopyrrole (DPP)-based donor–acceptor copolymers and the photophysical processes in bulk heterojunction solar cells using DPP copolymer:PC71BM blends are investigated by broadband transient absorption (TA) pump-probe experiments covering the vis–near-infrared spectral and fs–μs dynamic range. The experiments reveal surprisingly short exciton lifetimes in the pristine poly­mer films in conjunction with fast triplet state formation. An in-depth analysis of the TA data by multivariate curve resolution analysis shows that in blends with fullerene as acceptor ultrafast exciton dissociation creates charge carriers, which then rapidly recombine on the sub-ns timescale. Furthermore, at the carrier densities created by pulsed laser excitation the charge carrier recombination leads to a substantial population of the polymer triplet state. In fact, virtually quantitative formation of triplet states is observed on the sub-ns timescale. However, the quantitative triplet formation on the sub-ns timescale is not in line with the power conversion efficiencies of devices indicating that triplet state formation is an intensity-dependent process in these blends and is reduced under solar illumination conditions, as free charge carriers can be extracted from the photoactive layer in devices.

  14. Cooperative singlet and triplet exciton transport in tetracene crystals visualized by ultrafast microscopy

    Science.gov (United States)

    Wan, Yan; Guo, Zhi; Zhu, Tong; Yan, Suxia; Johnson, Justin; Huang, Libai

    2015-10-01

    Singlet fission presents an attractive solution to overcome the Shockley-Queisser limit by generating two triplet excitons from one singlet exciton. However, although triplet excitons are long-lived, their transport occurs through a Dexter transfer, making them slower than singlet excitons, which travel by means of a Förster mechanism. A thorough understanding of the interplay between singlet fission and exciton transport is therefore necessary to assess the potential and challenges of singlet-fission utilization. Here, we report a direct visualization of exciton transport in single tetracene crystals using transient absorption microscopy with 200 fs time resolution and 50 nm spatial precision. These measurements reveal a new singlet-mediated transport mechanism for triplets, which leads to an enhancement in effective triplet exciton diffusion of more than one order of magnitude on picosecond to nanosecond timescales. These results establish that there are optimal energetics of singlet and triplet excitons that benefit both singlet fission and exciton diffusion.

  15. Sub-ns triplet state formation by non-geminate recombination in PSBTBT:PC 70 BM and PCPDTBT:PC 60 BM organic solar cells

    KAUST Repository

    Etzold, Fabian

    2015-03-02

    The solid-state morphology and photo-generated charge carrier dynamics in low-bandgap polymer:fullerene bulk heterojunction photovoltaic blends using the donor–acceptor type copolymers PCPDTBT or its silicon-substituted analogue PSBTBT as donors are compared by two-dimensional (2D) solid-state nuclear magnetic resonance (NMR) and femto-to microsecond broadband Vis-NIR transient absorption (TA) pump–probe spectroscopy. The 2D solid-state NMR experiments demonstrate that the film morphology of PCPDTBT:PC60BM blends processed with additives such as octanedithiol (ODT) are similar to those of PSBTBT:PC60BM blends in terms of crystallinity, phase segregation, and interfacial contacts. The TA experiments and analysis of the TA data by multivariate curve resolution (MCR) reveal that after exciton dissociation and free charge formation, fast sub-nanosecond non-geminate recombination occurs which leads to a substantial population of the polymer\\'s triplet state. The extent to which triplet states are formed depends on the initial concentration of free charges, which itself is controlled by the microstructure of the blend, especially in case of PCPDTBT:PC60BM. Interestingly, PSBTBT:PC70BM blends show a higher charge generation efficiency, but less triplet state formation at similar free charge carrier concentrations. This indicates that the solid-state morphology and interfacial structures of PSBTBT:PC70BM blends reduces non-geminate recombination, leading to superior device performance compared to optimized PCPDTBT:PC60BM blends.

  16. Theoretical study of the intensity of chemically induce dynamic electron polarization of radical-triplet pairs

    Institute of Scientific and Technical Information of China (English)

    XU Xin-sheng; ZHANG Xian-yi; ZHANG Wei-jun; CUI Zhi-feng; LU Tong-xing

    2003-01-01

    Considering the interaction between excited triplet molecule and doublet radical, based on the second-order perturbation theory and the motion equation of density matrix, the polarization intensity of RTPM were theoretically calculated with the overpopulated doublet spin states and quartet spin states of radical-triplet pairs as initial conditions respectively. The results of calculation indicate that the net emissive polarization and the net absorptive polarization on the radical result from the zero-field-splitting (zfs) and the multiplet A/E and E/A polarization result from hyperfine (hf) interactions of the triplet molecule. The hyperfine related A+A/E or E+E/A CIDEP on the radical were the overpopulation of the net absorptive or emissive polarization and multiplet A/E or E/A polarization..

  17. Formation of the O I resonance triplet and intercombination doublet in the solar chromosphere

    International Nuclear Information System (INIS)

    Spectrum synthesis calculations are presented for the O I resonance triplet at 1304 A and the intercombination doublet at 1358 A for the solar atmosphere of Vernazza, Avrett, and Loeser and several variants, allowing for triplet fluorescence by the Lyβ emission of H I. Profiles, synthesized from a seven-level plus continuum O I atom are compared to observations taken with the high-resolution spectrometer on OSO 8, calibrated with the irradiance measurements of Heroux and Higgins. We find tha the O I triplet emission is dominated by the Lyβ fluorescence and that the agreement between observations and profiles computed with current chromospheric models is much improved over earlier studies

  18. On the behaviour of the IR Ca II triplet in normal and active galaxies

    International Nuclear Information System (INIS)

    Ca II triplet in absorption at λλ8498,8542,8662 A is the strongest feature in the infrared spectrum of late-type stars and normal galaxies. Its strength has been found to be a good luminosity indicator for metal-rich stellar populations. We present high signal-to-noise near-IR spectroscopic data for the nuclear region of 42 normal and active galaxies. We have explored the behaviour of the Ca II triplet strength and found that it shows a small spread around a mean value of 7 A for our sample of normal galaxies. We also found that, in all the Seyfert type 2 galaxies measured and even in some Seyfert type 1, while the optical stellar features show substantial dilution, the strength of the IR Ca II triplet is equal to and in some cases larger than that in normal elliptical galaxies. (author)

  19. Conditions for describing triplet states in reduced density matrix functional theory

    CERN Document Server

    Theophilou, Iris; Helbig, Nicole

    2016-01-01

    We consider necessary conditions for the one body-reduced density matrix (1RDM) to correspond to a triplet wave-function of a two electron system. The conditions concern the occupation numbers and are different for the high spin projections, $S_z=\\pm 1$, and the $S_z=0$ projection. We employ these conditions in reduced density matrix functional theory calculations for the triplet excitations of two electron systems. In addition, we propose that these conditions can be used in the calculation of triplet states of systems with more than two electrons by restricting the active space and assess this procedure in calculations for a few atomic and molecular systems. We show that the quality of the optimal 1RDMs improves by applying the conditions in all the cases we studied.

  20. Conditions for Describing Triplet States in Reduced Density Matrix Functional Theory.

    Science.gov (United States)

    Theophilou, Iris; Lathiotakis, Nektarios N; Helbig, Nicole

    2016-06-14

    We consider necessary conditions for the one-body reduced density matrix (1RDM) to correspond to a triplet wave function of a two-electron system. The conditions concern the occupation numbers and are different for the high spin projections, Sz = ±1, and the Sz = 0 projection. Hence, they can be used to test if an approximate 1RDM functional yields the same energies for both projections. We employ these conditions in reduced density matrix functional theory calculations for the triplet excitations of two-electron systems. In addition, we propose that these conditions can be used in the calculation of triplet states of systems with more than two electrons by restricting the active space. We assess this procedure in calculations for a few atomic and molecular systems. We show that the quality of the optimal 1RDMs improves by applying the conditions in all the cases we studied. PMID:27171683

  1. Inelastic collisions of ultracold triplet Rb$_\\textbf{2}$ molecules in the rovibrational ground state

    CERN Document Server

    Drews, Björn; Jachymski, Krzysztof; Idziaszek, Zbigniew; Denschlag, Johannes Hecker

    2016-01-01

    Exploring inelastic and reactive collisions on the quantum level is a main goal of the developing field of ultracold chemistry. We present first experimental studies of inelastic collisions of metastable ultracold triplet molecules in the vibrational ground state. The measurements are performed with nonpolar Rb$_2$ dimers which are prepared in precisely-defined quantum states and trapped in an array of quasi-1D potential tubes. We investigate collisions of molecules in the lowest triplet energy level where any inelastic process requires a relaxation to the singlet state. These are compared to two sets of collision experiments, carried out either with triplet molecules that have two quanta of rotational angular momentum or with vibrationally highly excited Feshbach molecules. We find no evidence for suppression of the inelastic collisions due to the necessary spin-flip, shedding light on this so far unsettled issue. For each of the molecular states studied here, we extract the decay rate constant and compare t...

  2. Dark matter and a suppression mechanism for neutrino masses in the Higgs triplet model

    CERN Document Server

    Kanemura, Shinya

    2012-01-01

    We extend the Higgs triplet model so as to include dark matter candidates and a simple suppression mechanism for the vacuum expectation value (v_Delta) of the triplet scalar field. The smallness of neutrino masses can be naturally explained with the suppressed value of v_Delta even when the triplet fields are at the TeV scale. The Higgs sector is extended by introducing Z_2-odd scalars (an SU(2)_L doublet eta and a real singlet s_2^0) in addition to a Z_2-even complex singlet scalar s_1^0 whose vacuum expectation value violates the lepton number conservation by a unit. In our model, v_Delta is generated by the one-loop diagram to which Z_2-odd particles contribute. The lightest Z_2-odd scalar boson can be a candidate for the dark matter. We briefly discuss a characteristic signal of our model at the LHC.

  3. Neutrino masses, anomalous U(1) gauge symmetry and doublet-triplet splitting

    International Nuclear Information System (INIS)

    We propose an attractive scenario of grand unified theories in which doublet-triplet splitting is naturally realized in SO(10) unification using the Dimopoulos-Wilczek mechanism. The anomalous U(1)A gauge symmetry plays an essential role in the double-triplet splitting mechanism. It is interesting that the anomalous U(1)A charges determine the unification scale and mass spectrum of additional particles, as well as the order of the Yukawa couplings of quarks and leptons. For the neutrino sector, bi-maximal mixing angles are naturally obtained, and proton decay via dimension 5 operators is suppressed. It is suggestive that the anomalous U(1)A gauge symmetry motivated by superstring theory effectively solves the two biggest problems in grand unified theories, the fermion mass hierarchy problem and doublet-triplet splitting problem. (author)

  4. A Memristive Model Compatible with Triplet Rule for Spike-Timing-Dependent-Plasticity

    CERN Document Server

    Cai, Weiran; Ellinger, Frank

    2011-01-01

    In this paper, we propose an extended version of the memristive STDP model, which is one of the most important and exciting recent discoveries in neuromorphic engineering. The proposed model aims to claim compatibility with another importent STDP rule beyond the pair-based rule, known as the triplet STDP rule. This is an extension of the asynchronous memristive model of Linares-Barranco, et al., capable of explaining the pair-based rule based on the analogy of the synapse to the memristor. The proposed new model is compatible with both the pair-baed and triplet-based rule, by assuming a mechanism of variable thresholds adapting to synaptic potentiation and depression. The dynamical process is governed by ordinary differential equations. The model is an expression of Froemke's principle of suppression for triplet rules and reveals a similar time dependence with that in the suppression STDP model.

  5. Autler-Townes multiplet spectroscopy

    Science.gov (United States)

    Ghafoor, F.

    2014-03-01

    The Autler-Townes doublet and triplet spectroscopy are well known in the literature. Here, atomic systems for quartuplet, quintuplet emission spectroscopy and their linkages with the sodium atom are investigated for display of the corresponding spectra. We explore the involved fundamental processes of quantum interference in these systems by examining the Laplace transform of the corresponding state-vector subjected to steady coherent illumination in the rotating wave approximation and Weisskopf-Wigner treatment of spontaneous emission as a simplest probability loss. In the quartuplet (quintuplet), four (five) fields interact appropriately and resonantly with the five-level (six-level) atom. The spectral profile of the single decaying level, upon interaction with three (four) other levels, splits into four (five) destructively interfering dressed states generating three (four) dark lines in the spectrum. These dark lines divide the spectrum into four (five) spectral components (bright lines) whose widths are effectively controlled by the relative strength of the laser fields and the relative width of a single decaying level. The idea is also extended to higher-ordered spectroscopy. The apparent disadvantage of these schemes is the successive increase in the number of laser fields required for the strongly interactive atomic states. However, these complexities are naturally inherited and are the beauty of these atomic systems. They provide the foundations for the basic mechanisms of the quantum interference involved in the higher-ordered multiplet spectroscopy.

  6. Ultrafast spectroscopy of linear carbon chains: the case of dinaphthylpolyynes

    Directory of Open Access Journals (Sweden)

    Negro M.

    2013-03-01

    Full Text Available The dynamics of excited streets in a special class of linear carbon chains, e.g. dinaphthyl polyynes, has been investigated by ultrafast transient absorption spectroscopy and DFT//TDDFT calculations. The ultrafast formation of a narrow photo-induced absorption band has been observed and assigned to an inter-system crossing event bringing to the formation of triplet excited streets.

  7. Codon size reduction as the origin of the triplet genetic code.

    Directory of Open Access Journals (Sweden)

    Pavel V Baranov

    Full Text Available The genetic code appears to be optimized in its robustness to missense errors and frameshift errors. In addition, the genetic code is near-optimal in terms of its ability to carry information in addition to the sequences of encoded proteins. As evolution has no foresight, optimality of the modern genetic code suggests that it evolved from less optimal code variants. The length of codons in the genetic code is also optimal, as three is the minimal nucleotide combination that can encode the twenty standard amino acids. The apparent impossibility of transitions between codon sizes in a discontinuous manner during evolution has resulted in an unbending view that the genetic code was always triplet. Yet, recent experimental evidence on quadruplet decoding, as well as the discovery of organisms with ambiguous and dual decoding, suggest that the possibility of the evolution of triplet decoding from living systems with non-triplet decoding merits reconsideration and further exploration. To explore this possibility we designed a mathematical model of the evolution of primitive digital coding systems which can decode nucleotide sequences into protein sequences. These coding systems can evolve their nucleotide sequences via genetic events of Darwinian evolution, such as point-mutations. The replication rates of such coding systems depend on the accuracy of the generated protein sequences. Computer simulations based on our model show that decoding systems with codons of length greater than three spontaneously evolve into predominantly triplet decoding systems. Our findings suggest a plausible scenario for the evolution of the triplet genetic code in a continuous manner. This scenario suggests an explanation of how protein synthesis could be accomplished by means of long RNA-RNA interactions prior to the emergence of the complex decoding machinery, such as the ribosome, that is required for stabilization and discrimination of otherwise weak triplet codon

  8. Triplet excited state properties in variable gap π-conjugated donor–acceptor–donor chromophores

    KAUST Repository

    Cekli, Seda

    2016-02-12

    A series of variable band-gap donor–acceptor–donor (DAD) chromophores capped with platinum(II) acetylide units has been synthesized and fully characterized by electrochemical and photophysical methods, with particular emphasis placed on probing triplet excited state properties. A counter-intuitive trend of increasing fluorescence quantum efficiency and lifetime with decreasing excited state energy (optical gap) is observed across the series of DAD chromophores. Careful study of the excited state dynamics, including triplet yields (as inferred from singlet oxygen sensitization), reveals that the underlying origin of the unusual trend in the fluorescence parameters is that the singlet–triplet intersystem crossing rate and yield decrease with decreasing optical gap. It is concluded that the rate of intersystem crossing decreases as the LUMO is increasingly localized on the acceptor unit in the DAD chromophore, and this result is interpreted as arising because the extent of spin–orbit coupling induced by the platinum heavy metal centers decreases as the LUMO is more localized on the acceptor. In addition to the trend in intersystem crossing, the results show that the triplet decay rates follow the Energy Gap Law correlation over a 1.8 eV range of triplet energy and 1000-fold range of triplet decay rates. Finally, femtosecond transient absorption studies for the DAD chromophores reveals a strong absorption in the near-infrared region which is attributed to the singlet excited state. This spectral band appears to be general for DAD chromophores, and may be a signature of the charge transfer (CT) singlet excited state.

  9. Transient absorption probe of intermolecular triplet excimer of naphthalene in fluid solutions: Identification of the species based on comparison to the intramolecular triplet excimers of covalently-linked dimers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Kofron, W.G.; Kong, S.; Rajesh, C.S.; Modarelli, D.A.; Lim, E.C.

    2000-02-24

    The authors report here the observation of the laser-induced transient absorption spectrum of intermolecular triplet excimers of naphthalene in fluid solution. This assignment is confirmed by comparison to the transient absorption spectra of the intramolecular triplet excimers of covalently linked dimers of naphthalene and quinoxaline.

  10. Preferential Nucleosome Assembly at DNA Triplet Repeats from the Myotonic Dystrophy Gene

    Science.gov (United States)

    Wang, Yuh-Hwa; Amirhaeri, Sorour; Kang, Seongman; Wells, Robert D.; Griffith, Jack D.

    1994-07-01

    The expansion of CTG repeats in DNA occurs in or near genes involved in several human diseases, including myotonic dystrophy and Huntington's disease. Nucleosomes, the basic structural element of chromosomes, consist of 146 base pairs of DNA coiled about an octamer of histone proteins and mediate general transcriptional repression. Electron microscopy was used to examine in vitro the nucleosome assembly of DNA containing repeating CTG triplets. The efficiency of nucleosome formation increased with expanded triplet blocks, suggesting that such blocks may repress transcription through the creation of stable nucleosomes.

  11. Signatures of Higgs-Triplet representations at TeV-e+e- colliders

    International Nuclear Information System (INIS)

    The authors investigate the potential of future TeV linear e+e- colliders to observe singly-charged Higgs bosons (H±) via the coupling H±W-+Z, which would signal the existence of exotic Higgs representations. In the context of a Higgs-triplet model compatible with the electroweak oblique parameters, they estimate the cross section for producing charged Higgs-triplet bosons that couple predominantly to W and Z bosons in 0.5-2 TeV-e+e- colliders. The principal backgrounds are evaluated and the viability of the signal is discussed and illustrated

  12. Spectrally tunable mollow triplet emission from a coherently excited quantum dot in a microcavity

    DEFF Research Database (Denmark)

    Ulrich, Sven M.; Ates, Serkan; Reitzenstein, Stephan;

    2010-01-01

    Resonance fluorescence of excitonic s-shell emission from a coherently pumped single InGaAs/GaAs quantum dot inside a micropillar cavity has been investigated in dependence on optical pump power and laser detuning, respectively. For strong purely resonant excitation, Mollow triplet spectra with l...... large Rabi splittings of j~­j » 60¹eV have been observed. Laser detuning-dependent series revealed the pronounced asymmetry of the emission triplet as predicted by theory. From our data, an electrical dipole moment of ¹ » 17:8§0:5 Debye could be derived for the excitonic state....

  13. Toward Singlet-Triplet Bistable Nonalternant Kekulé Hydrocarbons: Azulene-to-Naphthalene Rearrangement.

    Science.gov (United States)

    Das, Soumyajit; Wu, Jishan

    2015-12-01

    Recent developments of open-shell singlet diradicaloids motivated the search for stable singlet-triplet bistable nonalternant polycyclic hydrocarbons. During the synthesis of this type of molecule, such as the dibenzo-cyclohepta[def]fluorene 3, an unexpected azulene-to-naphthalene rearrangement was observed at room temperature, which resulted in new nonalternant hydrocarbons 8a/8b with a closed-shell singlet ground state. These studies provided insight into the unique chemistry of azulene and challenges for the synthesis of singlet-triplet bistable polycyclic hydrocarbons. PMID:26569547

  14. Spin-Selective Generation of Triplet Nitrenes: Olefin Aziridination through Visible-Light Photosensitization of Azidoformates.

    Science.gov (United States)

    Scholz, Spencer O; Farney, Elliot P; Kim, Sangyun; Bates, Desiree M; Yoon, Tehshik P

    2016-02-01

    Azidoformates are interesting potential nitrene precursors, but their direct photochemical activation can result in competitive formation of aziridination and allylic amination products. Herein, we show that visible-light-activated transition-metal complexes can be triplet sensitizers that selectively produce aziridines through the spin-selective photogeneration of triplet nitrenes from azidoformates. This approach enables the aziridination of a wide range of alkenes and the formal oxyamination of enol ethers using the alkene as the limiting reagent. Preparative-scale aziridinations can be easily achieved under continuous-flow conditions.

  15. Charge Transfer and Triplet States in High Efficiency OPV Materials and Devices

    Science.gov (United States)

    Dyakonov, Vladimir

    2013-03-01

    The advantage of using polymers and molecules in electronic devices, such as light-emitting diodes (LED), field-effect transistors (FET) and, more recently, solar cells (SC) is justified by the unique combination of high device performance and processing of the semiconductors used. Power conversion efficiency of nanostructured polymer SC is in the range of 10% on lab scale, making them ready for up-scaling. Efficient charge carrier generation and recombination in SC are strongly related to dissociation of the primary singlet excitons. The dissociation (or charge transfer) process should be very efficient in photovoltaics. The mechanisms governing charge carrier generation, recombination and transport in SC based on the so-called bulk-heterojunctions, i.e. blends of two or more semiconductors with different electron affinities, appear to be very complex, as they imply the presence of the intermediate excited states, neutral and charged ones. Charge transfer states, or polaron pairs, are the intermediate states between free electrons/holes and strongly bound excitons. Interestingly, the mostly efficient OLEDs to date are based on the so-called triplet emitters, which utilize the triplet-triplet annihilation process. In SC, recent investigations indicated that on illumination of the device active layer, not only mobile charges but also triplet states were formed. With respect to triplets, it is unclear how these excited states are generated, via inter-system crossing or via back transfer of the electron from acceptor to donor. Triplet formation may be considered as charge carrier loss channel; however, the fusion of two triplets may lead to a formation of singlet excitons instead. In such case, a generation of charges by utilizing of the so far unused photons will be possible. The fundamental understanding of the processes involving the charge transfer and triplet states and their relation to nanoscale morphology and/or energetics of blends is essential for the

  16. Multiphoton ionization through the triplet states of Mg by linearly and circularly polarized laser pulses

    CERN Document Server

    Buica, Gabriela; 10.1103/PhysRevA.79.013419

    2013-01-01

    We theoretically study multiphoton ionization through the triplet states of Mg by linearly polarized (LP) and circularly polarized (CP) fs laser pulses. After the construction of the atomic basis using the frozen-core Hartree-Fock potential (FCHFP) as well as the model potential (MP) approaches for both singlet and triplet series which show rather good agreements with the existing data in terms of state energies and dipole matrix elements, we solve time-dependent Schr\\"{o}dinger equations with $3s3p$ $^{3}P_{1}$ as an initial state, and calculate the total ionization yield and photoelectron energy spectra (PES).

  17. Scattering and Recombination of Two Triplet Excitons in polymer light-emitting diodes

    CERN Document Server

    Meng, Y; Liu, X J; Wang, Y D; An, Z

    2010-01-01

    The scattering and recombination processes between two triplet excitons in conjugated polymers are investigated by using a nonadiabatic evolution method, based on an extended Su-Schrieffer-Heeger model including interchain interactions. Due to the interchain coupling, the electron and/or hole in the two triplet excitons can exchange. The results show that the recombination induces the formation of singlet excitons, excited polarons and biexcitons. Moreover, we also find the yields of these products, which can contribute to the emission, increase with the interchain coupling strength, in good agreement with results from experiments.

  18. Simulating Entanglement Dynamics of Singlet-Triplet Qubits Coupled to a Classical Transmission Line Resonator

    Science.gov (United States)

    Wolfe, Michael; Kestner, Jason

    Electrons confined in lateral quantum dots are promising candidates for scalable quantum bits. Particularly, singlet-triplet qubits can entangle electrostatically and offer long coherence times due to their weak interactions with the environment. However, fast two-qubit operations are challenging. We examine the dynamics of singlet triplet qubits capacitively coupled to a classical transmission line resonator driven near resonance. We numerically simulate the dynamics of the von Neumann entanglement entropy and investigate parameters of the coupling element that optimizes the operation time for the qubit.

  19. Constraining Inert Triplet dark matter by the LHC and FermiLAT

    International Nuclear Information System (INIS)

    We study collider phenomenology of inert triplet scalar dark matter at the LHC. We discuss possible decay of Higgs boson to dark matter candidate and apply current experimental data for invisible Higgs decay and Rγγ to constrain parameter space of our model. We also investigate constraints on dark matter coming from forthcoming measurement, RZγ and mono-Higgs production. We analytically calculate the annihilation cross section of dark matter candidate into 2γ and Zγ and then use FermiLAT data to put constraints on parameter space of Inert Triplet Model. We found that this limit can be stronger than the constraints provided by LUX experiment for low mass DM

  20. Light Absorption by Secondary Organic Aerosol Produced from Aqueous Reaction of Phenols with an Organic Excited Triplet State and Hydroxyl Radical

    Science.gov (United States)

    Smith, J.; Yu, L.; George, K.; Ruthenburg, T. C.; Dillner, A. M.; Zhang, Q.; Anastasio, C.

    2012-12-01

    Although reactions in atmospheric condensed phases can form and transform secondary organic aerosol (SOA), these reactions are not well represented in many air quality models. Previous experiments have focused on hydroxyl radical-mediated oxidation of low molecular weight precursors such as gyloxal and methylglyoxal. In our work we are examining aqueous SOA formed from phenols, which are emitted from biomass burning and formed from the oxidation of anthropogenic aromatics such as benzene and toluene. In this work we examine aqueous SOA production from oxidation of three phenols (phenol, guaiacol, syringol) and three benzene-diols (catechol, resorcinol, 1,4-hydroquinone) by hydroxyl radical (OH) and the triplet excited state of 3,4-dimethoxybenzaldehyde (DMB). Our focus is on light absorption by the reaction products, which we characterized by measuring UV-Vis spectra and calculating mass absorption coefficients. To understand the elemental and molecular composition of the SOA, we also analyzed the samples with high resolution mass spectrometry and infrared spectroscopy. Our results indicate that aqueous oxidation of phenols and benzene-diols via OH and triplet excited states efficiently produce SOA that is highly absorbing in the UV-A wavelengths, consists of both small and large molecular weight products, and is highly oxidized.

  1. Conformational instability of the lowest triplet state of the benzene nucleus: II. p-Xylene, the influence of substituents

    NARCIS (Netherlands)

    J.H. van der Waals; M.C. van Hemert; W.J. Buma

    1990-01-01

    A calculation of the potential-energy surface of the lowest triplet state of p-xylene as a function of the S8(,) distortion coordinate of the benzene skeleton has been made to learn more about the influence of substituents on the vibronically induced distortion of benzene in its metastable triplet s

  2. A practical O(n log2 i>n>) time algorithm for computing the triplet distance on binary trees

    DEFF Research Database (Denmark)

    Sand, Andreas; Brodal, Gerth Stølting; Fagerberg, Rolf;

    2013-01-01

    The triplet distance is a distance measure that compares two rooted trees on the same set of leaves by enumerating all sub-sets of three leaves and counting how often the induced topologies of the tree are equal or different. We present an algorithm that computes the triplet distance between two ...

  3. An optical--near-IR study of a triplet of super star clusters in the starburst core of M82

    CERN Document Server

    Westmoquette, M S; Smith, L J; Seth, A C; Gallagher, J S; O'Connell, R W; Ryon, J E; Silich, S; Mayya, Y D; Munoz-Tunon, C; Gonzalez, D Rosa

    2014-01-01

    We present HST/STIS optical and Gemini/NIFS near-IR IFU spectroscopy, and archival HST imaging of the triplet of super star clusters (A1, A2 and A3) in the core of the M82 starburst. Using model fits to the STIS spectra, and the weakness of red supergiant CO absorption features (appearing at ~6 Myr) in the NIFS H-band spectra, the ages of A2 and A3 are $4.5\\pm1.0$~Myr. A1 has strong CO bands, consistent with our previously determined age of $6.4\\pm0.5$~Myr. The photometric masses of the three clusters are 4--$7\\times10^5$~\\Msol, and their sizes are $R_{\\rm eff}=159$, 104, 59~mas ($\\sim$2.8, 1.8, 1.0~pc) for A1,2 and 3. The STIS spectra yielded radial velocities of $320\\pm2$, $330\\pm6$, and $336\\pm5$~\\kms\\ for A1,2, and 3, placing them at the eastern end of the $x_2$ orbits of M82's bar. Clusters A2 and A3 are in high density (800--1000~\\cmt) environments, and like A1, are surrounded by compact H\\two\\ regions. We suggest the winds from A2 and A3 have stalled, as in A1, due to the high ISM ambient pressure. We ...

  4. Modeling the NeIX Triplet Spectral Region of Capella with the Chandra and XMM-Newton Gratings

    CERN Document Server

    Ness, J U

    2003-01-01

    High resolution X-ray spectroscopy with the diffraction gratings of Chandra and XMM-Newton offers new chances to study a large variety of stellar coronal phenomena. A popular X-ray calibration target is Capella, which has been observed with all gratings with significant exposure times. We gathered together all available data of the HETGS (155ks), LETGS (219ks), and RGS (53ks) for comparative analysis focusing on the NeIX triplet at around 13.5A, a region that is severely blended by strong iron lines. We identify 18 emission lines in this region of the HEG spectrum, including many from FeXIX, and find good agreement with predictions from a theoretical model constructed using the Astrophysical Plasma Emission Code (APEC). The model uses an emission measure distribution derived from FeXV to FeXXIV lines. While these 18 emission lines cannot be isolated in the LETGS or RGS spectra, their wavelengths and fluxes as measured with HEG are consistent with the lower resolution spectra. In the Capella model for HEG, the...

  5. Photoprotection and triplet energy transfer in higher plants: the role of electronic and nuclear fluctuations.

    Science.gov (United States)

    Cupellini, Lorenzo; Jurinovich, Sandro; Prandi, Ingrid G; Caprasecca, Stefano; Mennucci, Benedetta

    2016-04-20

    Photosynthetic organisms employ several photoprotection strategies to avoid damage due to the excess energy in high light conditions. Among these, quenching of triplet chlorophylls by neighboring carotenoids (Cars) is fundamental in preventing the formation of singlet oxygen. Cars are able to accept the triplets from chlorophylls by triplet energy transfer (TET). We have here studied TET rates in CP29, a minor light-harvesting complex (LHC) of the Photosystem II in plants. A fully atomistic strategy combining classical molecular dynamics of the LHC in its natural environment with a hybrid time-dependent density functional theory/polarizable MM description of the TET is used. We find that the structural fluctuations of the pigment-protein complex can largely enhance the transfer rates with respect to those predicted using the crystal structure, reducing the triplet quenching times in the subnanosecond scale. These findings add a new perspective for the interpretation of the photoprotection function and its relation with structural motions of the LHC. PMID:27052105

  6. Conformational instability of the lowest triplet state of the benzene nucleus: I. The unsubstituted molecule

    NARCIS (Netherlands)

    J.H. van der Waals; M.C. van Hemert; W.J. Buma

    1990-01-01

    Experiments on benzene have established that its lowest triplet state (3B1u) is conformationally unstable owing to vibronic coupling with the next higher state (3E1u). This instability was found to be critically dependent on the influence of a crystal field. An analogous vibronic coupling is to be e

  7. Computational determination of the dominant triplet population mechanism in photoexcited benzophenone

    NARCIS (Netherlands)

    Sergentu, Dumitru-Claudiu; Maurice, Remi; Havenith, Remco W. A.; Broer, Ria; Roca-Sanjuan, Daniel

    2014-01-01

    In benzophenone, intersystem crossing occurs efficiently between the S-1(n pi(star)) state and the T-1 state of dominant n pi(star) character, leading to excited triplet states after photoexcitation. The transition mechanism between S-1(n pi(star)) and T-1 is still a matter of debate, despite severa

  8. Intra-molecular Triplet Energy Transfer is a General Approach to Improve Organic Fluorophore Photostability

    Science.gov (United States)

    Zheng, Qinsi; Jockusch, Steffen; Rodríguez-Calero, Gabriel G.; Zhou, Zhou; Zhao, Hong; Altman, Roger B.; Abruña, Héctor D.; Blanchard, Scott C.

    2015-01-01

    Bright, long-lasting and non-phototoxic organic fluorophores are essential to the continued advancement of biological imaging. Traditional approaches towards achieving photostability, such as the removal of molecular oxygen and the use of small-molecule additives in solution, suffer from potentially toxic side effects, particularly in the context of living cells. The direct conjugation of small-molecule triplet state quenchers, such as cyclooctatetraene (COT), to organic fluorophores has the potential to bypass these issues by restoring reactive fluorophore triplet states to the ground state through intra-molecular triplet energy transfer. Such methods have enabled marked improvement in cyanine fluorophore photostability spanning the visible spectrum. However, the generality of this strategy to chemically and structurally diverse fluorophore species has yet to be examined. Here, we show that the proximal linkage of COT increases the photon yield of a diverse range of organic fluorophores widely used in biological imaging applications, demonstrating that the intra-molecular triplet energy transfer mechanism is a potentially general approach for improving organic fluorophore performance and photostability. PMID:26700693

  9. Detection of Ca II absorption triplet in a circumnuclear H II region of NGC 3310

    OpenAIRE

    Terlevich, Elena; Angeles I. Díaz; Pastoriza, Miriani G.; Terlevich, Roberto; Dottori, Horacio

    1990-01-01

    This is an electronic version of an article published in Monthly Notices of the Royal Astronomical Society. Terlevich, E., Díaz, A.I., Pastoriza, M.G., Terlevich, R. and H. Dottori. Detection of Ca II absorption triplet in a circumnuclear H II region of NGC 3310. Monthly Notices of the Royal Astronomical Society 242 (1990): 48-51

  10. On the behaviour of the IR Ca II triplet in normal and active galaxies

    OpenAIRE

    Terlevich, Elena; Angeles I. Díaz; Terlevich, Roberto

    1990-01-01

    This is an electronic version of an article published in Monthly Notices of the Royal Astronomical Society. Terlevich, E., Díaz, A.I., Terlevich, R. On the behaviour of the IR Ca II triplet in normal and active galaxies. Monthly Notices of the Royal Astronomical Society 242 (1990): 271-284

  11. Long-range spin-triplet proximity effect in Josephson junctions with multilayered ferromagnets

    Energy Technology Data Exchange (ETDEWEB)

    Trifunovic, Luka [Department of Physics, University of Belgrade (RS); Department of Physics, University of Basel (Switzerland); Radovic, Zoran [Department of Physics, University of Belgrade (RS)

    2011-07-01

    We study theoretically the Josephson effect and pairing correlations in planar SF{sub 1}F{sub 2}S junctions that consist of conventional superconductors (S) connected through two metallic monodomain ferromagnets (F{sub 1} and F{sub 2}) with transparent interfaces. We solve self-consistently the Eilenberger equations for arbitrary orientation of in-plane magnetizations in the clean limit and for moderate disorder in ferromagnets. Both singlet and triplet pair amplitudes and the Josephson current-phase relations are calculated numerically. It is shown that for equally thick ferromagnetic layers (symmetric junctions) the long-range spin-triplet correlations are not dominant: For thin ferromagnetic layers all amplitudes are equally large, while for thick layers the long range triplet amplitude is very small. It is shown that for noncollinear magnetizations the long-range proximity effect can be dominant in highly non-symmetric SF{sub 1}F{sub 2}S junctions with particularly thin F{sub 1} and thick F{sub 2} ferromagnetic layers. We find that dominant triplet correlations in Josephson junctions with ferromagnetic bilayer always give dominant second harmonics in current-phase relations at low temperatures.

  12. The Predicted Spectrum and Singlet-Triplet Interaction of the Hypermetallic Molecule SrOSr

    Science.gov (United States)

    Ostojić, B.; Jensen, Per; Schwerdtfeger, P.; Bunker, P. R.

    2013-10-01

    In accordance with previous studies in our group on Be, Mg, and Ca hypermetallic oxides, we find that SrOSr has a linear X-1Σg+ ground electronic state and a very low lying first excited -3Σu+ triplet electronic state. No gas-phase spectrum of this molecule has been assigned yet, and to encourage and assist in its discovery we present a complete ab initio simulation, with absolute intensities, of the infrared absorption spectrum for both electronic states. The three-dimensional potential energy surfaces and the electric dipole moment surfaces of the X-1Σg+ and -3Σu+ electronic states are calculated using a multireference configuration interaction (MRCISD) approach in combination with internally contracted multireference perturbation theory (RS2C) based on complete active space self-consistent field (CASSCF) wave functions applying a Sadlej pVTZ basis set for both O and Sr and the Stuttgart relativistic small-core effective core potential for Sr. The infrared spectra are simulated using the MORBID program system. We also calculate vertical excitation energies and transition moments for several excited singlet and triplet electronic states in order to predict the positions and intensities of the most prominent singlet and triplet electronic absorption bands. Finally, for this heavy molecule, we calculate the singlet-triplet interaction matrix elements between close-lying vibronic levels of the X- and - electronic states and find them to be very small.

  13. Efficient Algorithms for Computing the Triplet and Quartet Distance Between Trees of Arbitrary Degree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas;

    2013-01-01

    degree of any node in the two trees. Within the same time bounds, our framework also allows us to compute the parameterized triplet and quartet distances, where a parameter is introduced to weight resolved (binary) topologies against unresolved (non-binary) topologies. The previous best algorithm...

  14. Tri-P-LETS: Changing the Face of High School Computer Science

    Science.gov (United States)

    Sherrell, Linda; Malasri, Kriangsiri; Mills, David; Thomas, Allen; Greer, James

    2012-01-01

    From 2004-2007, the University of Memphis carried out the NSF-funded Tri-P-LETS (Three P Learning Environment for Teachers and Students) project to improve local high-school computer science curricula. The project reached a total of 58 classrooms in eleven high schools emphasizing problem solving skills, programming concepts as opposed to syntax,…

  15. How disorder controls the kinetics of triplet charge recombination in semiconducting organic polymer photovoltaics.

    Science.gov (United States)

    Bittner, Eric R; Lankevich, Vladimir; Gélinas, Simon; Rao, Akshay; Ginger, David A; Friend, Richard H

    2014-10-14

    Recent experiments by Rao et al. (Nature, 2013, 500, 435-439) indicate that recombination of triplet charge-separated states is suppressed in organic polymer-fullerene based bulk-heterojunction (BHJ) photovoltaic cells exhibiting a high degree of crystallinity in the fullerene phase relative to systems with more disorder. In this paper, we use a series of Frenkel-exciton lattice models to rationalize these results in terms of wave-function localization, interface geometry, and density of states. In one-dimensional co-linear and co-facial models of the interface, increasing local energetic disorder in one phase localizes the interfacial triplet charge-transfer ((3)CT) states and increases the rate at which these states relax to form lower-energy triplet excitons. In two dimensional BHJ models, energetic disorder within the fullerene phase plays little role in further localizing states pinned to the interface. However, inhomogeneous broadening introduces strong coupling between the interfacial (3)CT and nearby fullerene triplet excitons and can enhance the decay of these states in systems with higher degrees of energetic disorder.

  16. Electronic structure of thienylene vinylene oligomers : Singlet excited states, triplet excited states, cations, and dications

    NARCIS (Netherlands)

    Grozema, FC; van Duijnen, PT; Siebbeles, LDA; Goossens, A

    2004-01-01

    This paper describes a quantum chemical study of the electronic structure of thienylene vinylene oligomers ranging in size from two thienylene rings (2TV) to 12TV. The geometries of the TV oligomers in the ground state, the lowest triplet state, and the singly and doubly oxidized states were optimiz

  17. Photoprotection and triplet energy transfer in higher plants: the role of electronic and nuclear fluctuations.

    Science.gov (United States)

    Cupellini, Lorenzo; Jurinovich, Sandro; Prandi, Ingrid G; Caprasecca, Stefano; Mennucci, Benedetta

    2016-04-28

    Photosynthetic organisms employ several photoprotection strategies to avoid damage due to the excess energy in high light conditions. Among these, quenching of triplet chlorophylls by neighboring carotenoids (Cars) is fundamental in preventing the formation of singlet oxygen. Cars are able to accept the triplets from chlorophylls by triplet energy transfer (TET). We have here studied TET rates in CP29, a minor light-harvesting complex (LHC) of the Photosystem II in plants. A fully atomistic strategy combining classical molecular dynamics of the LHC in its natural environment with a hybrid time-dependent density functional theory/polarizable MM description of the TET is used. We find that the structural fluctuations of the pigment-protein complex can largely enhance the transfer rates with respect to those predicted using the crystal structure, reducing the triplet quenching times in the subnanosecond scale. These findings add a new perspective for the interpretation of the photoprotection function and its relation with structural motions of the LHC.

  18. How disorder controls the kinetics of triplet charge recombination in semiconducting organic polymer photovoltaics.

    Science.gov (United States)

    Bittner, Eric R; Lankevich, Vladimir; Gélinas, Simon; Rao, Akshay; Ginger, David A; Friend, Richard H

    2014-10-14

    Recent experiments by Rao et al. (Nature, 2013, 500, 435-439) indicate that recombination of triplet charge-separated states is suppressed in organic polymer-fullerene based bulk-heterojunction (BHJ) photovoltaic cells exhibiting a high degree of crystallinity in the fullerene phase relative to systems with more disorder. In this paper, we use a series of Frenkel-exciton lattice models to rationalize these results in terms of wave-function localization, interface geometry, and density of states. In one-dimensional co-linear and co-facial models of the interface, increasing local energetic disorder in one phase localizes the interfacial triplet charge-transfer ((3)CT) states and increases the rate at which these states relax to form lower-energy triplet excitons. In two dimensional BHJ models, energetic disorder within the fullerene phase plays little role in further localizing states pinned to the interface. However, inhomogeneous broadening introduces strong coupling between the interfacial (3)CT and nearby fullerene triplet excitons and can enhance the decay of these states in systems with higher degrees of energetic disorder. PMID:24922118

  19. Thermodynamic properties of the phase transitions in a class of spin-triplet ferromagnetic superconductors

    International Nuclear Information System (INIS)

    Magnetic susceptibility, entropy and specific heat are calculated at the equilibrium points of phase transition to a phase of coexistence of ferromagnetic order and superconductivity in a new class of spin-triplet ferromagnetic superconductors. The results are discussed in a view of application to metallic ferromagnets as UGe2, ZrZn2, URhGe. (authors)

  20. Maternal and Fetal Outcomes of Triplet Gestation in a Tertiary Hospital in Oman

    Directory of Open Access Journals (Sweden)

    Maryam Al-Shukri

    2014-05-01

    Full Text Available Objectives: The aim of this study was to describe the fetal and maternal outcomes of triplet gestation and to report on the maternal characteristics of those pregnancies in a tertiary care centre in Oman. Methods: A retrospective study was undertaken of all triplet pregnancies delivered at Sultan Qaboos University Hospital, Muscat, Oman, between January 2009 and December 2011. Results: Over the three-year study period, there were 9,140 deliveries. Of these, there were 18 triplet pregnancies, giving a frequency of 0.2%. The mean gestational age at delivery was 31.0 ± 3.0 weeks, and the mean birth weight was 1,594 ± 460 g. The most common maternal complications were preterm labour in 13 pregnancies (72.2%, gestational diabetes in 7 (39% and gestational hypertension in 5 (28%. Of the total deliveries, there were 54 neonates. Neonatal complications among these included hyaline membrane disease in 25 neonates (46%, hyperbilirubinaemia in 24 (43%, sepsis in 18 (33% and anaemia in 8 (15%. The perinatal mortality rate was 55 per 1,000 births. Conclusion: The maternal and neonatal outcomes of triplet pregnancies were similar to those reported in other studies.

  1. Quadrupole Magnet Error Sensitivities for FODO-Cell and Triplet Lattices in the LCLS Undulator

    International Nuclear Information System (INIS)

    The error sensitivities of quadrupole magnets in the LCLS FEL undulator are compared for a FODO-cell lattice and for a triplet lattice. The comparisons are made at a radiation wavelength of 1.5 (angstrom), where electron-to-photon phase errors are very sensitive to small trajectory variations in misaligned quadrupoles between the undulator sections. The results show that the triplet lattice is extremely sensitive, with triplet pitch and yaw alignment tolerances of ∼100 (micro)rad. The FODO-cell lattice, with its shorter, weaker quadrupoles is much more error tolerant with pitch and yaw tolerances of ∼2.5 mrad. Several other magnet errors are examined and categorized as trajectory, phase slip, and beam size effects. In nearly all cases, the FODO-cell lattice is much less sensitive with technologically achievable tolerance levels, while the triplet lattice tolerances are, in many cases, near achievable limits and may not be sustainable over the long term. Table 2 presents a brief tolerance comparison for the two lattice types

  2. Parenting Stress, Infant Emotion Regulation, Maternal Sensitivity, and the Cognitive Development of Triplets: A Model for Parent and Child Influences in a Unique Ecology

    Science.gov (United States)

    Feldman, Ruth; Eidelman, Arthur I.; Rotenberg, Noa

    2004-01-01

    To examine the development of triplets, 23 sets of triplets were matched with 23 sets of twins and 23 singletons (N138). Maternal sensitivity was observed at newborn, 3, 6, and 12 months, and infants' cognitive and symbolic skills at 1 year. Triplets received lower maternal sensitivity across infancy and exhibited poorer cognitive competencies…

  3. Circular dichroism and UV melting studies on formation of an intramolecular triplex containing parallel T*A:T and G*G:C triplets: netropsin complexation with the triplex.

    OpenAIRE

    Gondeau, C.; Maurizot, J C; Durand, M

    1998-01-01

    We have used circular dichroism and UV absorption spectroscopy to characterize the formation and melting behaviour of an intramolecular DNA triple helix containing parallel T*A:T and G*G:C triplets. Our approach to induce and to stabilize a parallel triplex involves the oligonucleotide 5'-d(G4A4G4[T4]C4T4C4-[T4]G4T4G4) ([T4] represents a stretch of four thymine residues). In a 10 mM sodium cacodylate, 0.2 mM disodium EDTA (pH 7) buffer, we have shown the following significant results. (i) Whi...

  4. OLEDs under high current densities. Transient electroluminescence turn-on peaks and singlet-triplet quenching

    Energy Technology Data Exchange (ETDEWEB)

    Kasemann, Daniel

    2012-02-27

    This work focuses on a better understanding of the behavior of organic light emitting devices (OLEDs) under intense electrical excitation. Attaining high exciton densities in organic semiconductors by electrical excitation is of special interest for the field of organic semiconductor lasers (OSLs). In these devices, the high singlet exciton density needed in the active layer to obtain population inversion is easily created by pulsed optical pumping, but direct electrical pumping has not been achieved yet. First, the steps necessary to achieve stable high current densities in organic semiconductors are discussed. After determining the optimal excitation scheme using single p-doped transport layers, the device complexity is increased up to full p-i-n OLEDs with their power dependent emission spectra. For this purpose, two exemplary emitter systems are chosen: the fluorescent laser dye 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM) doped into Aluminum(III)bis (2-methyl-8-quinolinato)-4-phenylphenolate (Alq{sub 3}) and the efficient phosphorescent emitter system N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine (alpha-NPD) doped by Iridium(III) bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate) (Ir(MDQ){sub 2}(acac)). For pulsed excitation using 50 ns pulses and a repetition rate of 1 kHz, single 100 nm thin p- and n-doped transport layers sustain current densities of over 6 kA/cm{sup 2}. While the maximum current density decreases with increasing device thickness, the full OLEDs still sustain current densities beyond 800 A/cm{sup 2} and exhibit a continuously increasing emission intensity with increasing input power. Next, the time-resolved emission behavior of the singlet and triplet emitter device at high excitation densities is analyzed on the nanosecond scale. Here, the peak emission intensity of the phosphorescent emitter system is found to be more than eight times lower than for the singlet emitter system at comparable current

  5. Terahertz spectroscopy

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd

    2009-01-01

    In this presentation I will review methods for spectroscopy in the THz range, with special emphasis on the practical implementation of the technique known ad THz time-domain spectroscopy (THz-TDS). THz-TDS has revived the old field of far-infrared spectroscopy, and enabled a wealth of new...... activities that promise commercial potential for spectroscopic applications in the THz range. This will be illustrated with examples of spectroscopy of liquids inside their bottles as well as sensitive, quantitative spectroscopy in waveguides....

  6. Thickness dependence of the triplet spin-valve effect in superconductor–ferromagnet–ferromagnet heterostructures

    Science.gov (United States)

    Zdravkov, Vladimir I; Kehrle, Jan-Michael; Obermeier, Günter; Ullrich, Aladin; Morari, Roman; Krug von Nidda, Hans-Albrecht; Müller, Claus; Kupriyanov, Mikhail Yu; Sidorenko, Anatolie S; Horn, Siegfried; Deminov, Rafael G; Tagirov, Lenar R; Tidecks, Reinhard

    2016-01-01

    Summary Background: In nanoscale layered S/F1/N/F2/AF heterostructures, the generation of a long-range, odd-in-frequency spin-projection one triplet component of superconductivity, arising at non-collinear alignment of the magnetizations of F1 and F2, exhausts the singlet state. This yields the possibility of a global minimum of the superconducting transition temperature T c, i.e., a superconducting triplet spin-valve effect, around mutually perpendicular alignment. Results: The superconducting triplet spin valve is realized with S = Nb a singlet superconductor, F1 = Cu41Ni59 and F2 = Co ferromagnetic metals, AF = CoOx an antiferromagnetic oxide, and N = nc-Nb a normal conducting (nc) non-magnetic metal, which serves to decouple F1 and F2. The non-collinear alignment of the magnetizations is obtained by applying an external magnetic field parallel to the layers of the heterostructure and exploiting the intrinsic perpendicular easy-axis of the magnetization of the Cu41Ni59 thin film in conjunction with the exchange bias between CoOx and Co. The magnetic configurations are confirmed by superconducting quantum interference device (SQUID) magnetic moment measurements. The triplet spin-valve effect has been investigated for different layer thicknesses, d F1, of F1 and was found to decay with increasing d F1. The data is described by an empirical model and, moreover, by calculations using the microscopic theory. Conclusion: The long-range triplet component of superconducting pairing is generated from the singlet component mainly at the N/F2 interface, where the amplitude of the singlet component is suppressed exponentially with increasing distance d F1. The decay length of the empirical model is found to be comparable to twice the electron mean free path of F1 and, thus, to the decay length of the singlet component in F1. Moreover, the obtained data is in qualitative agreement with the microscopic theory, which, however, predicts a (not investigated) breakdown of the

  7. Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

    Science.gov (United States)

    Nattestad, Andrew; Cheng, Yuen Yap; MacQueen, Rowan W.; Wallace, Gordon G.; Schmidt, Timothy W.

    2014-01-01

    The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date. PMID:25285452

  8. Integrating a triplet-triplet annihilation up-conversion system to enhance dye-sensitized solar cell response to sub-bandgap light.

    Science.gov (United States)

    Nattestad, Andrew; Cheng, Yuen Yap; MacQueen, Rowan W; Wallace, Gordon G; Schmidt, Timothy W

    2014-01-01

    The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date. PMID:25285452

  9. Energy distribution in CF 2( 1B 1) from the triplet-triplet annihilation of CF 2( 3B 1) and from the vacuum ultraviolet photolysis of C 2F 4

    Science.gov (United States)

    Koda, Seiichiro

    1980-02-01

    Spectral analysis of the CF 2( 1B 1) → CF 2( 1A 1) transition showed that the energy distribution found in the v2 bending vibration ( v'2 ⩽ 3) of CF 2( 1B 1) produced from the triplet-triplet annihilation of CF 2( 3B 1) and from the vacuum ultraviolet photolysis of C 2F 4 are approximately statistical and closely related to each other.

  10. Using less Quantum Resource for Probabilistic Controlled Teleportation of a Triplet W State

    Directory of Open Access Journals (Sweden)

    Xian-Ming Wang

    2012-10-01

    Full Text Available In a recent paper [CHIN. PHYS. LETT. Vol.26,No.7(2009070306 ], DONG et al. proposed a scheme for probabilistic controlled teleportation of a triplet W state using combined non-maximally entangled channel of two Einstein–Podolsky–Rosen (EPR states and one Greenberger–Horne–Zeilinger (GHZ state. In this paper ,only using one Einstein–Podolsky–Rosen (EPR state and one Greenberger–Horne–Zeilinger (GHZ state,the scheme for probabilistic controlled teleportation of a triplet W state is presented. Furthermore, Comparing with the widely used Bell-State measurement, Alice performs orthogonal complete basis measurement in the current work. Then Bob can faithfully reconstruct the original state by performing relevant unitary transformations. The total probability of successful teleportation is only dependent on channel coefficients of EPR state and GHZ state.  

  11. Quench Limit Calculation for Steady State Heat Deposits in LHC Inner Triplet Magnets

    CERN Document Server

    Cerutti, F; Esposito, L S; Siemko, A; Bocian, D

    2012-01-01

    In hadron colliders such as the LHC, the energy deposited in the superconductors by the particles lost from the beams or coming from the collision debris may provoke quenches detrimental to the accelerator operation. A Network Model is used to simulate the thermodynamic behavior of the superconducting magnets. In previous papers the validations of network model with measurements performed in the CERN and Fermilab magnet test facilities were presented. This model was subsequently used for thermal analysis of the current LHC inner triplet quadrupole magnets for beam energy of 3.5 TeV and 7.0 TeV. The detailed study of helium cooling channels efficiency for energy deposits simulated with FLUKA was performed. The expected LHC inner triplet magnets quench limit is presented.

  12. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for liquid mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Ploetz, Elizabeth A.; Smith, Paul E. [Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506 (United States)

    2015-03-07

    Kirkwood-Buff or Fluctuation Solution Theory can be used to provide experimental pair fluctuations, and/or integrals over the pair distribution functions, from experimental thermodynamic data on liquid mixtures. Here, this type of approach is used to provide triplet and quadruplet fluctuations, and the corresponding integrals over the triplet and quadruplet distribution functions, in a purely thermodynamic manner that avoids the use of structure factors. The approach is then applied to binary mixtures of water + methanol and benzene + methanol over the full composition range under ambient conditions. The observed correlations between the different species vary significantly with composition. The magnitude of the fluctuations and integrals appears to increase as the number of the most polar molecule involved in the fluctuation or integral also increases. A simple physical picture of the fluctuations is provided to help rationalize some of these variations.

  13. Superfluid phases of triplet pairing and rapid cooling of the neutron star in Cassiopeia A

    Directory of Open Access Journals (Sweden)

    Lev B. Leinson

    2015-02-01

    Full Text Available In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A.

  14. Effect of isoscalar spin-triplet pairings on spin-isospin responses in $sd-$ shell nuclei

    CERN Document Server

    Sagawa, H; Sasano, M

    2016-01-01

    The spin magnetic dipole transitions and the neutron-proton spin-spin correlations in $sd-$shell even-even nuclei with $N=Z$ are investigated using shell model wave functions. The isoscalar spin-triplet pairing correlation provides a substantial quenching effect on the spin magnetic dipole transitions, especially the isovector (IV) ones. Consequently, an enhanced isoscalar spin-triplet pairing interaction influences the proton-neutron spin-spin correlation deduced from the difference between the isoscalar (IS) and the IV sum rule strengths. The effect of the $\\Delta$ ($\\Delta_{33}$ resonance)-hole coupling is examined in the IV spin transition and the spin-spin correlations of the ground states.

  15. Photopolymer material sensitized by xanthene dyes for holographic recording using forbidden singlet-triplet electronic transitions

    Science.gov (United States)

    Shelkovnikov, Vladimir; Vasiljev, Evgeny; Russkih, Vladimlen; Berezhnaya, Viktoria

    2016-07-01

    A new holographic photopolymer material is developed. The photopolymer material is sensitized by dyes of xanthene and thioxanthene series which contain iodine and bromine heavy atoms. Holographic recording was carried out during excitation of forbidden singlet-triplet electron transitions of dyes. Thioerythrosin triethylammonium was identified as the most effective sensitizer among a number of tested dyes. The spectral absorption area of the singlet-triplet electronic transition of the dye is conveyed in the red spectral range from 600 to 700 nm. The sensitivity of the photopolymer material to radiation with 633 nm wavelength is 180 mJ cm-2. Optimization of concentration of the main components of the photopolymer compositions was carried out in order to achieve maximum efficiency of holographic recording.

  16. TripNet: A Method for Constructing Phylogenetic Networks from Triplets

    CERN Document Server

    Tusserkani, Ruzbeh; Poormohammadi, Hadi; Azadi, Azin

    2011-01-01

    We present TripNet, a method for constructing phylogenetic networks from triplets. We will present the motivations behind our approach and its theoretical and empirical justification. To demonstrate the accuracy and efficiency of TripNet, we performed two simulations and also applied the method to five published data sets: Kreitman's data, a set of triplets from real yeast data obtained from the Fungal Biodiversity Center in Utrecht, a collection of 110 highly recombinant Salmonella multi-locus sequence typing sequences, and nrDNA ITS and cpDNA JSA sequence data of New Zealand alpine buttercups of Ranunculus sect. Pseudadonis. Finally, we compare our results with those already obtained by other authors using alternative methods. TripNet, data sets, and supplementary files are freely available for download at (www.bioinf.cs.ipm.ir/softwares/tripnet).

  17. He II Heat Exchanger Test Unit for the LHC Inner Triplet

    CERN Document Server

    Blanco-Viñuela, E; Huang, Y; Nicol, T H; Peterson, T; Van Weelderen, R

    2002-01-01

    The Inner Triplet Heat Exchanger Test Unit (IT-HXTU) is a 30-m long thermal model designed at Fermilab, built in US industry, fully automated and tested at CERN as part of the US LHC program to develop the LHC Interaction Region quadrupole system. The cooling scheme of the IT-HXTU is based on heat exchange between stagnant pressurized He II in the magnet cold mass and saturated He II (two-phase) flowing in a heat exchanger located outside of and parallel to the cold mass. The purposes of this test are, among others, to validate the proposed cooling scheme and to define an optimal control strategy to be implemented in the future LHC accelerator. This paper discusses the results for the heat exchanger test runs and emphasizes the thermal and hydraulic behavior of He II for the inner triplet cooling scheme.

  18. Catalogues of isolated galaxies, isolated pairs, and isolated triplets in the local Universe

    CERN Document Server

    Argudo-Fernández, M; Bergond, G; Puertas, S Duarte; Carmona, E Ramos; Sabater, J; Lorenzo, M Fernández; Espada, D; Sulentic, J; Ruiz, J E; Leon, S

    2015-01-01

    The construction of catalogues of galaxies and the posterior study of galaxy properties in relation to their environment, have been hampered by the scarce redshift information. The new 3-dimensional (3D) surveys permits to distinguish small, faint, physically bound satellites from a background projected galaxy population, giving a more comprehensive 3D picture of the surroundings. We aim to provide representative samples of isolated galaxies, isolated pairs, and isolated triplets for testing galaxy evolution and secular processes in low density regions of the local Universe, as well as to characterise their local and large-scale environments. We use spectroscopic data from the SDSS to automatically and homogeneously compile catalogues of 3,702 isolated galaxies, 1,240 isolated pairs, and 315 isolated triplets in the local Universe. To quantify the effects of their local and large-scale environments, we compute the projected density and the tidal strength for the brightest galaxy in each sample. We find eviden...

  19. Triplet repeat DNA structures and human genetic disease: dynamic mutations from dynamic DNA

    Indian Academy of Sciences (India)

    Richard R Sinden; Vladimir N Potaman; Elena A Oussatcheva; Christopher E Pearson; Yuri L Lyubchenko; Luda S Shlyakhtenko

    2002-02-01

    Fourteen genetic neurodegenerative diseases and three fragile sites have been associated with the expansion of (CTG)n•(CAG)n, (CGG)n•(CCG)n, or (GAA)n•(TTC)n repeat tracts. Different models have been proposed for the expansion of triplet repeats, most of which presume the formation of alternative DNA structures in repeat tracts. One of the most likely structures, slipped strand DNA, may stably and reproducibly form within triplet repeat sequences. The propensity to form slipped strand DNA is proportional to the length and homogeneity of the repeat tract. The remarkable stability of slipped strand DNA may, in part, be due to loop-loop interactions facilitated by the sequence complementarity of the loops and the dynamic structure of three-way junctions formed at the loop-outs.

  20. Neutrino dark energy and leptogenesis with TeV scale triplets

    Energy Technology Data Exchange (ETDEWEB)

    Hati, Chandan [Physical Research Laboratory, Ahmedabad (India); Indian Institute of Technology Gandhinagar, Chandkheda, Ahmedabad (India); Sarkar, Utpal [Physical Research Laboratory, Ahmedabad (India)

    2016-05-15

    We propose a realization of mass varying neutrino dark energy in two extensions of the Standard Model (SM) with a dynamical neutrino mass related to the acceleron field while satisfying the naturalness. In the first scenario the SM is extended to include a TeV scale scalar Higgs triplet (ξ) and a TeV scale second Higgs doublet (η), while in the second scenario an extension of the SM with fermion triplet (Σ) is considered. We also point out the possible leptogenesis mechanisms for simultaneously generating the observed baryon asymmetry of the universe in both scenarios and discuss the collider signatures for the TeV scale new fields which make these models testable in the current run of LHC. (orig.)

  1. Singlet-Triplet Transitions of a P(o)schl-Teller Quantum Dot

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2006-01-01

    We study the energy spectra of a two-dimensional two-electron quantum dot (QD) with P(o)schl-Teller confining potential under the influence of perpendicular homogeneous magnetic field. Calculations are made by using the method of numerical diagonalization of Hamiltonian matrix within the effective-mass approximation. A ground-state behavior (spin singlet-triplet transitions) as a function of the strength of a magnetic field is found. We find that the dot radius R of a P(o)schl-Teller potential is important for the ground-state transition and the feature of ground-state for a P(o)schl-Teller QD and a parabolic QD is similar when R is larger. The larger the well depth, the higher the magnetic field for the singlet-triplet transition of the ground-state of two interacting electrons in a P(o)schl-Teller QD.

  2. Beginning Chemistry Teachers Use of the Triplet Relationship During their First Three Years in the Classroom

    Science.gov (United States)

    Adams, Krista

    Pedagogical content knowledge (PCK) has been described as the knowledge teachers' use in the process of designing and implementing lessons to a particular group of students. This includes the most effective representations that make the content understandable to students, together with the preconceptions and misconceptions that students hold. For chemistry, students have been found to have difficulty with the discipline due to its reliance upon three levels of representation called the triplet: the macro, the submicro, and the symbolic. This study examines eight beginning chemistry teachers' depiction of the chemistry content through the triplet relationship and modifications as a result of considering students' understanding across the teacher's first three years in the classroom. The data collected included classroom observations, interviews, and artifacts for the purpose of triangulation. The analysis of the data revealed that beginning chemistry teachers utilized the abstract components, submicro and symbolic, primarily in the first year. However, the teachers began to engage more macro representations over time building a more developed instructional repertoire. Additionally, teachers' developed an awareness of and responded to their students' understanding of learning atomic structure during the second and third year teaching. The results of this study call for preservice and induction programs to help novice chemistry teachers build a beginning repertoire that focuses on the triplet relationship. In so doing, the teachers enter the classroom with a repertoire that allows them to address the needs of their students. Finally, the study suggests that the triplet relationship framework should be revisited to include an additional component that frames learning to account for socioscientific issues and historical contributions.

  3. Spin-Triplet Andreev Reflection in Ferromagnet/Ferromangnet/s-Wave Superconductor Junctions

    Institute of Scientific and Technical Information of China (English)

    JI Yi-Qun; NIU Zhi-Ping; FENG Cui-Di; XING Ding-Yu

    2008-01-01

    Four-component Bogoliubov-de Gennes equations are applied to study the tunnelling conductance spectra G(E)of half-metallic ferromagnet/ferromagnet/s-wave superconductor tunnel junctions.It is found that only for noncollinear magnetizations,there exists nonzero G(E) structure within the energy gap,which is a signature of appearance of the novel Andreev reflection and spin-triplet pairing correlations.

  4. Quantum Computing via Singlet-Triplet Spin Qubits in Nanowire Double Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    XUE Peng

    2011-01-01

    We propose a new structure for quantum computing via spin qubits with high fidelity.Each spin qubit corresponds to two electrons in a nanowire double quantum dot,with the singlet and one of the triplets as the logical qubit states.The entangling gate is effected by virtual charge dipole transitions.We include noise to show the feasibility of this scheme under current experimental conditions.

  5. Fusion Rules of the ${\\cal W}_{p,q}$ Triplet Models

    CERN Document Server

    Wood, Simon

    2009-01-01

    In this paper we determine the fusion rules of the logarithmic ${\\calW}_{p,q}$ triplet theory and construct the Grothendieck group with subgroups for which consistent product structures can be defined. The fusion rules are then used to determine projective covers. This allows us also to write down a candidate for a modular invariant partition function. Our results demonstrate that recent work on the ${\\cal W}_{2,3}$ model generalises naturally to arbitrary (p,q).

  6. Implications of the discovery of a Higgs triplet on electroweak right-handed neutrinos

    CERN Document Server

    Aranda, Alfredo; Hung, P Q

    2008-01-01

    Electroweak scale active right-handed neutrinos such as those proposed in a recent model necessitate the enlargement of the SM Higgs sector to include Higgs triplets with doubly charged scalars. The search for and constraints on such Higgs sector has implications not only on the nature of the electroweak symmetry breaking but also on the possibility of testing the seesaw mechanism at colliders such as the LHC and the ILC.

  7. Adler-type sum rule, charge symmetry and neutral current in general multi-triplet model

    International Nuclear Information System (INIS)

    We derive Adler-type sum rule extended to general multi-triplet model. Paying attention to roles of the colour degree of freedom, we discuss the charge symmetry property of the weak charged current and the structure functions for ν(ν-)+N→l(l-)+X, and also the structure of the neutral current. A comment is given on implications in our theory of Koike and Konuma's result on the neutral hadronic current. (auth.)

  8. Identification of redundant and synergetic circuits in triplets of electrophysiological data

    Science.gov (United States)

    Erramuzpe, Asier; Ortega, Guillermo J.; Pastor, Jesus; de Sola, Rafael G.; Marinazzo, Daniele; Stramaglia, Sebastiano; Cortes, Jesus M.

    2015-12-01

    Objective. Neural systems are comprised of interacting units, and relevant information regarding their function or malfunction can be inferred by analyzing the statistical dependencies between the activity of each unit. While correlations and mutual information are commonly used to characterize these dependencies, our objective here is to extend interactions to triplets of variables to better detect and characterize dynamic information transfer. Approach. Our approach relies on the measure of interaction information (II). The sign of II provides information as to the extent to which the interaction of variables in triplets is redundant (R) or synergetic (S). Three variables are said to be redundant when a third variable, say Z, added to a pair of variables (X, Y), diminishes the information shared between X and Y. Similarly, the interaction in the triplet is said to be synergetic when conditioning on Z enhances the information shared between X and Y with respect to the unconditioned state. Here, based on this approach, we calculated the R and S status for triplets of electrophysiological data recorded from drug-resistant patients with mesial temporal lobe epilepsy in order to study the spatial organization and dynamics of R and S close to the epileptogenic zone (the area responsible for seizure propagation). Main results. In terms of spatial organization, our results show that R matched the epileptogenic zone while S was distributed more in the surrounding area. In relation to dynamics, R made the largest contribution to high frequency bands (14-100 Hz), while S was expressed more strongly at lower frequencies (1-7 Hz). Thus, applying II to such clinical data reveals new aspects of epileptogenic structure in terms of the nature (redundancy versus synergy) and dynamics (fast versus slow rhythms) of the interactions. Significance. We expect this methodology, robust and simple, can reveal new aspects beyond pair-interactions in networks of interacting units in other

  9. Complex bilateral polysyndactyly featuring a triplet of delta phalanges in a syndactylised digit

    International Nuclear Information System (INIS)

    The delta phalanx is a rare congenital skeletal anomaly. An abnormal C-shaped epiphysis is usually responsible for a progressive angular digital deformity observed either in hands or feet. Solitary delta phalanges are usually described. We report a case of bilateral congenital hand malformations featuring a triplet of delta phalanges affecting a single digit on one hand, together with a concealed central polydactyly on the other. (orig.)

  10. Photoinduced charge injection from excited triplet hypocrellin B into TiO2 colloid in ethanol

    Institute of Scientific and Technical Information of China (English)

    SHEN, Jian-Quan; SHEN, Tao; ZHANG, Man-Hua; LI, Wen; SONG, Ai-Min

    2000-01-01

    Photosensitization of TiO2 colloid by hypocrellin B (HB), a natural photodynamic pigment with extremely high plhotosta bility, has been studied by surface enhanced Raman spec troscorpy (SERS), laser flash photolysis and electron param agnetic resonance (EPR) techniques. The photosensitization of TiO2 occurred practically from the excited triplet dye and the electron injection rate constant is 1.3 × 106 s-1. The influ ences of donor and acceptor on the eleciron injection were in vestigated.

  11. Analysis of Triplet Exciton Loss Pathways in PTB7:PC71BM Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Kraus, Hannes; Heiber, Michael C.; Väth, Stefan; Kern, Julia; Deibel, Carsten; Sperlich, Andreas; Dyakonov, Vladimir

    2016-07-01

    A strategy for increasing the conversion efficiency of organic photovoltaics has been to increase the VOC by tuning the energy levels of donor and acceptor components. However, this opens up a new loss pathway from an interfacial charge transfer state to a triplet exciton (TE) state called electron back transfer (EBT), which is detrimental to device performance. To test this hypothesis, we study triplet formation in the high performing PTB7:PC71BM blend system and determine the impact of the morphology-optimizing additive 1,8-diiodoctane (DIO). Using photoluminescence and spin-sensitive optically detected magnetic resonance (ODMR) measurements at low temperature, we find that TEs form on PC71BM via intersystem crossing from singlet excitons and on PTB7 via EBT mechanism. For DIO blends with smaller fullerene domains, an increased density of PTB7 TEs is observed. The EBT process is found to be significant only at very low temperature. At 300 K, no triplets are detected via ODMR, and electrically detected magnetic resonance on optimized solar cells indicates that TEs are only present on the fullerenes. We conclude that in PTB7:PC71BM devices, TE formation via EBT is impacted by fullerene domain size at low temperature, but at room temperature, EBT does not represent a dominant loss pathway.

  12. Non-Linear Advanced Control of the LHC Inner Triplet Heat Exchanger Test Unit

    CERN Document Server

    Blanco-Viñuela, E; De Prada-Moraga, C; Cristea, S

    2002-01-01

    The future Large Hadron Collider (LHC) at CERN will include eight interaction region final focus magnet systems, the so-called "Inner Triplet", one on each side of the four beam collision points. The Inner Triplets will be cooled in a static bath of pressurized He II nominally at 1.9 K. This temperature is a control parameter and has very severe constraints in order to avoid the transition from the superconducting to normal resistive state. The main difference in these special zones with respect to a regular LHC cell is higher dynamic heat load unevenly distributed which modifies largely the process characteristics and hence the controller performance. Several control strategies have already been tested at CERN in a pilot plant (LHC String Test) which reproduced a LHC half-cell. In order to validate a common control structure along the whole LHC ring, a Nonlinear Model Predictive Control (NMPC) has been developed and implemented in the Inner Triplet Heat Exchanger Unit (IT-HXTU) at CERN. Automation of the Inn...

  13. Experimental evidences of singlet to triplet transition in a spin cluster compound

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Tanmoy [Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus, PO: BCKV Campus Main Office, Nadia, Mohanpur 741246, West Bengal (India); Experimental Physics III, Fakultät Physik, TU Dortmund, 44221 Dortmund (Germany); Singh, Harkirat [Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus, PO: BCKV Campus Main Office, Nadia, Mohanpur 741246, West Bengal (India); Department of Condensed Matter Physics and Material Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Mitra, Chiranjib, E-mail: chiranjib@iiserkol.ac.in [Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur Campus, PO: BCKV Campus Main Office, Nadia, Mohanpur 741246, West Bengal (India)

    2015-12-15

    Experimental realization of magnetic field induced singlet to triplet transition is reported for NH{sub 4}CuPO{sub 4}·H{sub 2}O, a two spin cluster material with isotropic Heisenberg interaction. Experimental magnetization and specific heat data have been collected as a function of temperature and magnetic field. Experimental data have been analyzed in terms of Heisenberg dimer model. Two quantum complementary observables representing local and non-local properties of the spins are constructed using the experimental data and a clear evidence of singlet to triplet transition is observed through partial quantum information sharing when the magnetic field is swept through a particular value. Signature of this transition has also been captured when specific heat is measured as a function of magnetic field. Furthermore, using the experimental specific heat data, magnetic energy values are calculated and their variations are captured as a function of magnetic field and temperature. - Highlights: • Magnetic field induced energy level crossing is reported for NH{sub 4}CuPO{sub 4}·H{sub 2}O. • Magnetic data are analyzed within the framework of spin 1/2 dimer model. • Singlet-triplet transition is captured employing quantum complementarity principle. • Field dependent specific heat data also provides the signature of the transition.

  14. Experimental evidences of singlet to triplet transition in a spin cluster compound

    International Nuclear Information System (INIS)

    Experimental realization of magnetic field induced singlet to triplet transition is reported for NH4CuPO4·H2O, a two spin cluster material with isotropic Heisenberg interaction. Experimental magnetization and specific heat data have been collected as a function of temperature and magnetic field. Experimental data have been analyzed in terms of Heisenberg dimer model. Two quantum complementary observables representing local and non-local properties of the spins are constructed using the experimental data and a clear evidence of singlet to triplet transition is observed through partial quantum information sharing when the magnetic field is swept through a particular value. Signature of this transition has also been captured when specific heat is measured as a function of magnetic field. Furthermore, using the experimental specific heat data, magnetic energy values are calculated and their variations are captured as a function of magnetic field and temperature. - Highlights: • Magnetic field induced energy level crossing is reported for NH4CuPO4·H2O. • Magnetic data are analyzed within the framework of spin 1/2 dimer model. • Singlet-triplet transition is captured employing quantum complementarity principle. • Field dependent specific heat data also provides the signature of the transition

  15. Fluorescence via Reverse Intersystem Crossing from Higher Triplet States in a Bisanthracene Derivative

    CERN Document Server

    Sato, Tohru; Haruta, Naoki; Pu, Yong-Jin

    2016-01-01

    To elucidate the high external quantum efficiency observed for organic light-emitting diodes using a bisanthracene derivative, BD1, as the emitting molecule, off-diagonal vibronic coupling constants (VCCs) between the excited states of BD1, which govern non-radiative transition rates, were calculated employing time-dependent density functional theory. The VCCs were analysed based on the concept of vibronic coupling density. The VCC calculations suggest a fluorescence via higher triplets (FvHT) mechanism, which entails the conversion of a T$_4$ exciton generated during electrical excitation into an S$_2$ exciton via reverse intersystem crossing (RISC); moreover, the S$_2$ exciton relaxes to a fluorescent S$_1$ exciton because of large vibronic coupling between S$_2$ and S$_1$. This mechanism is valid as long as the relaxation of triplet states higher than T$_1$ to lower states is suppressed. The symmetry-controlled thermally activated delayed fluorescence (SC-TADF) and inverted singlet and triplet (iST) struct...

  16. Magnetic dipolar interaction between correlated triplets created by singlet fission in tetracene crystals

    CERN Document Server

    Wang, Rui; Zhang, Bo; Liu, Yunlong; Wang, Xiaoyong; Xiao, Min

    2015-01-01

    Singlet fission (SF) can potentially break the Shockley-Queisser efficiency limit in single-junction solar cells by splitting one photo-excited singlet exciton (S1) into two triplets (2T1) in organic semiconductors. A dark multi-exciton (ME) state has been proposed as the intermediate connecting S1 to 2T1. However, the exact nature of this ME state, especially how the doubly-excited triplets interact, remains elusive. Here, we report a quantitative study on the magnetic dipolar interaction between SF-induced correlated triplets in tetracene crystals by monitoring quantum beats relevant to the ME sublevels at room temperature. The resonances of ME sublevels approached by tuning an external magnetic field are observed to be avoided, which agrees well with the theoretical predictions considering a magnetic dipolar interaction of ~ 0.008 GHz. Our work paves a way to quantify the magnetic dipolar interaction in organic materials and marks an important step towards understanding the underlying physics of the ME sta...

  17. Quantum dynamics study of singlet-triplet transitions in s-trans-1,3-butadiene

    Science.gov (United States)

    Nikoobakht, Behnam; Köppel, Horst

    2016-05-01

    The intersystem crossing dynamics of s-trans-1,3-butadiene in its lowest singlet and triplet states is studied theoretically, employing a fully quantal approach for the first time. The electronic states 21Ag, 11Bu, 13Bu and 13Ag, which interact vibronically and via the spin-orbit coupling are treated in the calculation, thus covering the lowest spin-forbidden electronic transitions. Up to five nuclear degrees of freedom, including out-of-plane dihedral angles are included in our investigation. The calculation of potential energy surfaces relies on the CASPT2 method, and the evaluation of spin-orbit coupling matrix elements using the full two-electron Breit-Pauli Hamiltonian is performed by utilizing the MRCI wavefunction. The latter dependence on the nuclear coordinates is included for the first time. An electronic population transfer on the sub-picosecond time scale due to intersystem crossing is obtained, a mechanism that can contribute to the singlet-triplet transitions in the electron energy loss spectrum of s-trans-1, 3-butadiene. It is found that the dependence of the spin-orbit coupling on the out-of-plane coordinates plays a dominant role in these singlet-triplet transitions. The amount of population transfer to the 13Ag and 13Bu states is roughly of the same order of magnitude.

  18. The protein's role in triplet energy transfer in bacterial reaction centers.

    Energy Technology Data Exchange (ETDEWEB)

    Laible, P. D.

    1998-08-14

    When photosynthetic organisms are subjected to high-light conditions in nature, electron transfer becomes blocked as the rate of conversion of light into charge-separated states in the reaction center (RC) exceeds the capacity of the soluble carriers involved in cyclic electron transfer. In that event, a well-characterized T{sub 0}-polarized triplet state {sup T}P, is formed on the primary donor, P, from the P{sup +}H{sub A}{sup {minus}} state (reviewed in [1]). In an aerobic or semi-aerobic environment, the major role of the carotenoid (C), also bound by the RC, is to quench {sup T}P prior to its sensitization of the {sup 1}{Delta}{sub g} singlet state of oxygen--a potentially damaging biological oxidant. The carotenoid performs this function efficiently in most bacterial RCs by rapidly accepting the triplet state from P and dissipating this excited-state energy into heat through internal conversion. The lowest-lying triplet states of P and the carotenoid are sufficiently different that {sup T}P can promote oxygen to its excited singlet state whereas {sup T}C can quench the {sup T}P state (reviewed in [2]).

  19. Analysis of Triplet Exciton Loss Pathways in PTB7:PC71BM Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Kraus, Hannes; Heiber, Michael C.; Väth, Stefan; Kern, Julia; Deibel, Carsten; Sperlich, Andreas; Dyakonov, Vladimir

    2016-01-01

    A strategy for increasing the conversion efficiency of organic photovoltaics has been to increase the VOC by tuning the energy levels of donor and acceptor components. However, this opens up a new loss pathway from an interfacial charge transfer state to a triplet exciton (TE) state called electron back transfer (EBT), which is detrimental to device performance. To test this hypothesis, we study triplet formation in the high performing PTB7:PC71BM blend system and determine the impact of the morphology-optimizing additive 1,8-diiodoctane (DIO). Using photoluminescence and spin-sensitive optically detected magnetic resonance (ODMR) measurements at low temperature, we find that TEs form on PC71BM via intersystem crossing from singlet excitons and on PTB7 via EBT mechanism. For DIO blends with smaller fullerene domains, an increased density of PTB7 TEs is observed. The EBT process is found to be significant only at very low temperature. At 300 K, no triplets are detected via ODMR, and electrically detected magnetic resonance on optimized solar cells indicates that TEs are only present on the fullerenes. We conclude that in PTB7:PC71BM devices, TE formation via EBT is impacted by fullerene domain size at low temperature, but at room temperature, EBT does not represent a dominant loss pathway. PMID:27380928

  20. Providing power for miniaturized medical implants: triplet sensitization of semiconductor surfaces.

    Science.gov (United States)

    Benniston, Andrew C; Harriman, Anthony; Yang, Songjie

    2013-07-28

    Here, we recognize the growing significance of miniaturized devices as medical diagnostic tools and highlight the need to provide a convenient means of powering such instruments when implanted into the body. One of the most promising approaches to this end involves using a light-collection facility to absorb incident white light and transfer the photonic energy to a tiny semiconductor embedded on the device. Although fluorescent organic molecules offer strong potential as modules for such solar collectors, we emphasize the promise offered by transition metal complexes. Thus, an extended series of binuclear Ru(II)/Os(II) poly(pyridine) complexes has been shown to be highly promising sensitizers for amorphous silicon solar cells. These materials absorb a high fraction of visible light while the Ru(II)-based units possess triplet energies that are comparable to those of the naphthalene-based bridge. The metal complex injects a triplet exciton into the bridge and this, in turn, is trapped by the Os(II)-based terminal. The result is extremely efficacious triplet-energy transfer; at room temperature the rate of energy transfer is independent of distance over some 6 nm and only weakly dependent on temperature. PMID:23776300

  1. A cationic dye triplet as a unique "glue" that can connect fully matched termini of DNA duplexes.

    Science.gov (United States)

    Kashida, Hiromu; Hayashi, Takamitsu; Fujii, Taiga; Asanuma, Hiroyuki

    2011-02-25

    In this study, we propose that three consecutive cationic p-methylstilbazoles tethered on D-threoninols (Z residues) at 5' termini act as a unique "glue" connecting DNA duplexes by their interstrand cluster formation. Interstrand clustering of p-methylstilbazoles (ZZZ triplets) induces narrowing and hypsochromic shift of bands at 350 nm, which can be assigned to the absorption of p-methylstilbazole. However, single-stranded DNA conjugates involving a ZZZ triplet at the 5' terminus of 8-mer native nucleotides is found not to induce such large spectral changes, which implies that the intrinsic self-assembling property of ZZZ triplets is weak. Interestingly, when this conjugate is hybridized with a complementary 8-mer native oligonucleotide, a remarkable spectral change is observed, indicating the dimerization of a duplex through the interstrand clustering of ZZZ triplets. Dimerization of the duplex is also evidenced by cold-spray ionization mass spectrometry. This interstrand clustering is observed only when a ZZZ triplet is tethered to a 5' rather than 3' terminus. Furthermore, the stability of the interstrand cluster increases by increasing the number of nucleobases of the DNA portion, and when mismatched base pairs are incorporated or when a base next to the Z residue is deleted, the stability substantially drops. When we apply the ZZZ triplet to the formation of a nanowire using two complementary DNA conjugates, each of which has a ZZZ triplet at the 5' termini as overhang, we demonstrate the successful formation of a nanowire by native PAGE analysis. Since native sticky ends that have three nucleotides do not serve as "glue", ZZZ triplets with their unique glue-like properties are prime candidates for constructing DNA-based nanoarchitectures. PMID:21305625

  2. 3D phase-matching conditions for the generation of entangled triplets by chi(2) interlinked interactions

    OpenAIRE

    Bondani, Maria; Allevi, Alessia; Gevinti, Eleonora; Agliati, Andrea; Andreoni, Alessandra

    2006-01-01

    An analytical calculation of the interaction geometry of two interlinked second-order nonlinear processes fulfilling phase-matching conditions is presented. The method is developed for type-I uniaxial crystals and gives the positions on a screen beyond the crystal of the entangled triplets generated by the interactions. The analytical results are compared to experiments realized in the macroscopic regime. Preliminary tests to identify the triplets are also performed based on intensity correla...

  3. Determining the electronic triplet-singlet transition probability in double quantum dots: Analogy with the double slit experiment

    OpenAIRE

    Domínguez, Fernando; Platero, Gloria

    2009-01-01

    We apply an elementary measurement scheme to calculate the electronic triplet-singlet transition mediated by hyperfine interaction in a double quantum dot. We show how the local character of the hyperfine interaction and the nuclear back-action process (flip-flop) are crucial to cancel destructive interferences of the triplet-singlet transition probability. It is precisely this cancellation which differentiates the hyperfine interaction from an anisotropic magnetic field which mixes the tripl...

  4. Photo-assisted intersystem crossing: The predominant triplet formation mechanism in some isolated polycyclic aromatic molecules excited with pulsed lasers

    International Nuclear Information System (INIS)

    Naphthalene, anthracene, and phenanthrene are shown to have very long-lived triplet lifetimes when the isolated molecules are excited with nanosecond pulsed lasers resonant with the lowest singlet state. For naphthalene, triplet state populations are created only during the laser pulse, excluding the possibility of normal intersystem crossing at the one photon level, and all molecules have triplet lifetimes greater than hundreds of microseconds, similar to the behavior previously reported for phenylacetylene. Although containing 7-12 thousand cm-1 of vibrational energy, the triplet molecules have ionization thresholds appropriate to vibrationless T1 states. The laser power dependences (slopes of log-log power plots) of the excited singlet and triplet populations are about 0.7 for naphthalene and about 0.5 for anthracene. Kinetic modeling of the power dependences successfully reproduces the experimental results and suggests that the triplet formation mechanism involves an enhanced spin orbit coupling caused by sigma character in states at the 2-photon level. Symmetry Adapted Cluster-Configuration Interaction calculations produced excited state absorption spectra to provide guidance for estimating kinetic rates and the sigma character present in higher electronic states. It is concluded that higher excited state populations are significant when larger molecules are excited with pulsed lasers and need to be taken into account whenever discussing the molecular photodynamics

  5. Triplet Pair Correlations in s-Wave Superfluids as a Signature of the Fulde-Ferrell-Larkin-Ovchinnikov State

    Science.gov (United States)

    Zapata, I.; Sols, F.; Demler, E.

    2012-10-01

    We show that antiparallel triplet pairing correlations are generated in superfluids with purely s-wave interactions whenever population imbalance enforces anisotropic Fulde-Ferrell (FF) or inhomogeneous Larkin-Ovchinikov (LO) states. These triplet correlations appear in the Cooper pair wave function, while the triplet part of the gap remains zero. The same set of quasiparticle states contributes to the triplet component and to the polarization, thus spatially correlating them. In the LO case, this set forms a narrow band of Andreev states centered on the nodes of the s-wave order parameter. This picture naturally provides a unifying explanation of previous findings that attractive p-wave interaction stabilizes FFLO states. We also study a similar triplet mixing which occurs when a balanced two-component system displays FFLO-type oscillations due to a spin-dependent optical lattice. We discuss how this triplet component can be measured in systems of ultracold atoms using a rapid ramp across a p-wave Feshbach resonance. This should provide a smoking gun signature of FFLO states.

  6. Dissecting galaxy triplets in the Sloan Digital Sky Survey Data Release 10: I. Stellar populations and emission line analysis

    CERN Document Server

    Costa-Duarte, M V; Duplancic, F; Sodré, L; Lambas, D G

    2016-01-01

    We identify isolated galaxy triplets in a volume-limited sample from the Sloan Digital Sky Survey Data Release 10. Our final sample has 80 galaxy systems in the redshift range 0.04$\\le$z$\\le$0.1, brighter than $M_r = -20.5 + 5\\log h_{70}$. Spectral synthesis results and WHAN and BPT diagnostic diagrams were employed to classify the galaxies in these systems as star-forming, active nuclei, or passive/retired. Our results suggest that the brightest galaxies drive the triplet evolution, as evidenced by the strong correlations between properties as mass assembly and mean stellar population age with triplet properties. Galaxies with intermediate luminosity or the faintest one within the triplet seem to play a secondary role. Moreover, the relation between age and stellar mass of galaxies is similar for these galaxies but different for the brightest galaxy in the system. Most of the triplet galaxies are passive or retired, according to the WHAN classification. Low mass triplets present different fractions of WHAN c...

  7. An optical-near-IR study of a triplet of super star clusters in the starburst core of M82

    Energy Technology Data Exchange (ETDEWEB)

    Westmoquette, M. S. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany); Bastian, N. [Excellence Cluster Universe, Boltzmannstrasse 2, D-85748 Garching bei München (Germany); Smith, L. J. [Space Telescope Science Institute and European Space Agency, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Seth, A. C. [University of Utah, Salt Lake City, UT 84112 (United States); Gallagher III, J. S.; Ryon, J. E. [Department of Astronomy, University of Wisconsin-Madison, 5534 Sterling, 475 North Charter Street, Madison, WI 53706 (United States); O' Connell, R. W. [Department of Astronomy, University of Virginia, P.O. Box 3818, Charlottesville, VA 22903 (United States); Silich, S.; Mayya, Y. D.; González, D. Rosa [Instituto Nacional de Astrofísica, Optica y Electronica, Luis Enrique Erro 1, Tonantzintla, C.P. 72840, Puebla (Mexico); Muñoz-Tuñón, C., E-mail: westmoquette@gmail.com [Instituto de Astrofísica de Canarias, C/vía Láctea s/n, E-38200 La Laguna, Tenerife (Spain)

    2014-07-10

    We present HST/STIS optical and Gemini/NIFS near-IR IFU spectroscopy and archival Hubble Space Telescope (HST) imaging of the triplet of super star clusters (A1, A2, and A3) in the core of the M82 starburst. Using model fits to the Space Telescope Imaging Spectrograph (STIS) spectra and the weakness of red supergiant CO absorption features (appearing at ∼6 Myr) in the NIFS H-band spectra, the ages of A2 and A3 are 4.5 ± 1.0 Myr. A1 has strong CO bands, consistent with our previously determined age of 6.4 ± 0.5 Myr. The photometric masses of the three clusters are 4-7 × 10{sup 5} M{sub ☉}, and their sizes are R{sub eff} = 159, 104, 59 mas (∼2.8, 1.8, 1.0 pc) for A1, A2, and A3. The STIS spectra yielded radial velocities of 320 ± 2, 330 ± 6, and 336 ± 5 km s{sup –1} for A1, A2, and A3, placing them at the eastern end of the x{sub 2} orbits of M82's bar. Clusters A2 and A3 are in high-density (800-1000 cm{sup –3}) environments, and like A1, are surrounded by compact H II regions. We suggest the winds from A2 and A3 have stalled, as in A1, due to the high ISM ambient pressure. We propose that the three clusters were formed in situ on the outer x{sub 2} orbits in regions of dense molecular gas subsequently ionized by the rapidly evolving starburst. The similar radial velocities of the three clusters and their small projected separation of ∼25 pc suggest that they may merge in the near future unless this is prevented by velocity shearing.

  8. The Complementarity of the Loop to the Stem in DNA Pseudoknots Gives Rise to Local TAT Base-Triplets.

    Science.gov (United States)

    Reiling-Steffensmeier, Calliste; Marky, Luis A

    2016-01-01

    Pseudoknots belong to an RNA structural motif that has significant roles in the biological function of RNA. An example is ribosomal frameshifting; in this mechanism, the formation of a local triplex changes the reading frame that allows for differences in the translation of mRNAs. In this work, we have used a combination of temperature-dependent UV spectroscopy and differential scanning calorimetry (DSC) to determine the unfolding thermodynamics of a set of DNA pseudoknots with the following sequence: d(TCTCTTnAAAAAAAAGAGAT5TTTTTTT), where "Tn" is a thymine loop with n=5 (PsK-5), 7 (PsK-7), 9 (PsK-9), or 11 (PsK-11). All four oligonucleotides form intramolecular pseudoknots, and the increase in the length of this loop yielded more stable pseudoknots due to higher transition temperatures and higher unfolding enthalpies. This indicates formation of one and three TAT/TAT stacks in PsK-9 and PsK-11, respectively. We have flipped one AT for a TA base pair in the core stem of these pseudoknots, preventing in this way the formation of these base-triplet stacks. The DSC curves of these pseudoknots yielded lower unfolding enthalpies, confirming the formation of a local triplex in PsK-9 and PsK-11. Furthermore, we have investigated the reaction of PsK-5 and PsK-9 with their partially complementary strands: directly by isothermal titration calorimetry and indirectly by creating a Hess cycle with the DSC data. Relative to the PsK-5 reaction, PsK-9 reacts with its complementary strand with less favorable free energy and enthalpy contributions; this indicates PsK-9 is more stable and more compact due to the formation of a local triplex.

  9. The Complementarity of the Loop to the Stem in DNA Pseudoknots Gives Rise to Local TAT Base-Triplets.

    Science.gov (United States)

    Reiling-Steffensmeier, Calliste; Marky, Luis A

    2016-01-01

    Pseudoknots belong to an RNA structural motif that has significant roles in the biological function of RNA. An example is ribosomal frameshifting; in this mechanism, the formation of a local triplex changes the reading frame that allows for differences in the translation of mRNAs. In this work, we have used a combination of temperature-dependent UV spectroscopy and differential scanning calorimetry (DSC) to determine the unfolding thermodynamics of a set of DNA pseudoknots with the following sequence: d(TCTCTTnAAAAAAAAGAGAT5TTTTTTT), where "Tn" is a thymine loop with n=5 (PsK-5), 7 (PsK-7), 9 (PsK-9), or 11 (PsK-11). All four oligonucleotides form intramolecular pseudoknots, and the increase in the length of this loop yielded more stable pseudoknots due to higher transition temperatures and higher unfolding enthalpies. This indicates formation of one and three TAT/TAT stacks in PsK-9 and PsK-11, respectively. We have flipped one AT for a TA base pair in the core stem of these pseudoknots, preventing in this way the formation of these base-triplet stacks. The DSC curves of these pseudoknots yielded lower unfolding enthalpies, confirming the formation of a local triplex in PsK-9 and PsK-11. Furthermore, we have investigated the reaction of PsK-5 and PsK-9 with their partially complementary strands: directly by isothermal titration calorimetry and indirectly by creating a Hess cycle with the DSC data. Relative to the PsK-5 reaction, PsK-9 reacts with its complementary strand with less favorable free energy and enthalpy contributions; this indicates PsK-9 is more stable and more compact due to the formation of a local triplex. PMID:26794363

  10. Prediction of plant promoters based on hexamers and random triplet pair analysis

    Directory of Open Access Journals (Sweden)

    Noman Nasimul

    2011-06-01

    Full Text Available Abstract Background With an increasing number of plant genome sequences, it has become important to develop a robust computational method for detecting plant promoters. Although a wide variety of programs are currently available, prediction accuracy of these still requires further improvement. The limitations of these methods can be addressed by selecting appropriate features for distinguishing promoters and non-promoters. Methods In this study, we proposed two feature selection approaches based on hexamer sequences: the Frequency Distribution Analyzed Feature Selection Algorithm (FDAFSA and the Random Triplet Pair Feature Selecting Genetic Algorithm (RTPFSGA. In FDAFSA, adjacent triplet-pairs (hexamer sequences were selected based on the difference in the frequency of hexamers between promoters and non-promoters. In RTPFSGA, random triplet-pairs (RTPs were selected by exploiting a genetic algorithm that distinguishes frequencies of non-adjacent triplet pairs between promoters and non-promoters. Then, a support vector machine (SVM, a nonlinear machine-learning algorithm, was used to classify promoters and non-promoters by combining these two feature selection approaches. We referred to this novel algorithm as PromoBot. Results Promoter sequences were collected from the PlantProm database. Non-promoter sequences were collected from plant mRNA, rRNA, and tRNA of PlantGDB and plant miRNA of miRBase. Then, in order to validate the proposed algorithm, we applied a 5-fold cross validation test. Training data sets were used to select features based on FDAFSA and RTPFSGA, and these features were used to train the SVM. We achieved 89% sensitivity and 86% specificity. Conclusions We compared our PromoBot algorithm to five other algorithms. It was found that the sensitivity and specificity of PromoBot performed well (or even better with the algorithms tested. These results show that the two proposed feature selection methods based on hexamer frequencies

  11. Chemical spectroscopy

    International Nuclear Information System (INIS)

    The purpose of chemical spectroscopy with neutrons is to utilize the dependence of neutron scattering cross-sections on isotope and on momentum transfer (which probes the spatial extent of the excitation) to understand fundamental and applied aspects of the dynamics of molecules and fluids. Chemical spectroscopy is divided into three energy ranges: vibrational spectroscopy, 25-500 MeV, for which much of the work is done on Be-filter analyzer instruments; low energy spectroscopy, less than 25 MeV; and high resolution spectroscopy, less than 1 MeV, which typically is performed on backscattering spectrometers. Representative examples of measurements of the Q-depenence of vibrational spectra, higher energy resolution as well as extension of the Q-range to lower values at high energy transfers, and provisions of higher sensitivities in vibrational spectroscopy are discussed. High resolution, high sensitivity, and polarization analysis studies in low energy spectroscopy are discussed. Applications of very high resolution spectroscopy are also discussed

  12. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  13. Spectroscopy and photophysics of self-organized zinc porphyrin nanolayers. 3. Fluorescence detected magnetic resonance of triplet states

    NARCIS (Netherlands)

    Schaafsma, T.J.; Dag, I.; Sitters, R.; Glasbeek, M.; Lifshitz, E.

    2005-01-01

    Fluorescence detected magnetic resonance (FDMR) has been applied to ~25-nm-thick porphyrin films, containing ordered domains of zinc tetra-(p-octylphenyl)-porphyrin (ZnTOPP) spin-coated onto quartz slides. Illuminating the films at 1.4 K with 457.9-nm light from a continuous wave Ar+ laser produces

  14. Laser-Induced Magnetic Dipole Spectroscopy.

    Science.gov (United States)

    Hintze, Christian; Bücker, Dennis; Domingo Köhler, Silvia; Jeschke, Gunnar; Drescher, Malte

    2016-06-16

    Pulse electron paramagnetic resonance measurements of nanometer scale distance distributions have proven highly effective in structural studies. They exploit the magnetic dipole-dipole coupling between spin labels site-specifically attached to macromolecules. The most commonly applied technique is double electron-electron resonance (DEER, also called pulsed electron double resonance (PELDOR)). Here we present the new technique of laser-induced magnetic dipole (LaserIMD) spectroscopy based on optical switching of the dipole-dipole coupling. In a proof of concept experiment on a model peptide, we find, already at a low quantum yield of triplet excitation, the same sensitivity for measuring the distance between a porphyrin and a nitroxide label as in a DEER measurement between two nitroxide labels. On the heme protein cytochrome C, we demonstrate that LaserIMD allows for distance measurements between a heme prosthetic group and a nitroxide label, although the heme triplet state is not directly observable by an electron spin echo. PMID:27163749

  15. Desempenho comunicativo em trigêmeos prematuros Acquisition and development language in premature triplets

    Directory of Open Access Journals (Sweden)

    Amanda Tragueta Ferreira

    2008-03-01

    Full Text Available OBJETIVO: descrever habilidades do desenvolvimento de trigêmeos aos 18 meses e aos 29 meses de vida, enfocando a comunicação. MÉTODOS: irmãos trigêmeos dizigóticos do sexo masculino. Os procedimentos de avaliação englobaram: Anamnese, Observação do Comportamento Comunicativo e Escala de Desenvolvimento de Gesell e Amatruda (2000. As avaliações foram realizadas aos 18 e aos 29 meses. As crianças apresentaram atraso do desenvolvimento neuropsicomotor e eram expostas a multilingüismo. RESULTADOS: foi verificada alteração nos comportamentos comunicativos nas três crianças, tanto na primeira quanto na segunda avaliação, embora tenha sido observada melhora do desempenho, após as orientações recebidas pela família. Na segunda avaliação foi observada criptofasia. Dos comportamentos motor grosseiro, delicado, adaptativo, pessoal-social e de linguagem, o último foi o mais afetado para as três crianças, apesar de todos estarem alterados considerando a idade cronológica dos trigêmeos. CONCLUSÃO: as habilidades do desenvolvimento dos trigêmeos avaliados neste estudo estavam alteradas, acometendo todas as áreas. Ressalta-se maior comprometimento da linguagem tanto aos 18 como aos 29 meses.PURPOSE: to describe abilities of triplets' development by 18 months and the 29 months of life, focusing on communication. METHODS: dizygotic male sibling triplets. The evaluation procedures included history of disease, observing the communicative behavior and Escala de Desenvolvimento de Gesell e Amatruda (2000. The evaluations were accomplished by the 18 months and the 29 months. The children showed delay in the neuropshycomotor development and were exposed to multilingualism. RESULTS: alteration was verified in the communicative behaviors in the three children, both in the first as well as in the second evaluation, although an amelioration was shown in the performance, after the orientations received by the family. Cryptophasia was

  16. Relationship between dopant energy levels and device performances of triplet mixed host devices

    International Nuclear Information System (INIS)

    Device performances of phosphorescent organic light-emitting diodes (PHOLEDs) with triplet mixed host structure were correlated with dopant energy levels and mixed host composition. A mixed host of 4,4',4''-tris-(N-carbazolyl)triphenylamine (TCTA) and spirobifluorene type host (PH1) was used and three different dopants with different bandgap were doped in the mixed host. Optimum quantum efficiency was obtained in TCTA:PH1 (50:50) mixed host device in the case of green dopants, while the optimum host composition for red and orange dopants was TCTA:PH1 (25:75)

  17. Inelastic and elastic collision rates for triplet states of ultracold strontium

    CERN Document Server

    Traverso, A; de Escobar, Y N Martinez; Mickelson, P G; Nagel, S B; Yan, M; Killian, T C

    2008-01-01

    We report measurement of the inelastic and elastic collision rates for ^{88}Sr atoms in the (5s5p)^3P_0 state in a crossed-beam optical dipole trap. This is the first measurement of ultracold collision properties of a ^3P_0 level in an alkaline-earth atom or atom with similar electronic structure. Since the (5s5p)^3P_0 state is the lowest level of the triplet manifold, large loss rates indicate the importance of principle-quantum-number-changing collisions at short range. We also provide an estimate of the collisional loss rates for the (5s5p){^3P_2} state.

  18. Inelastic and elastic collision rates for triplet states of ultracold strontium

    Science.gov (United States)

    Traverso, A.; Chakraborty, R.; Martinez de Escobar, Y. N.; Mickelson, P. G.; Nagel, S. B.; Yan, M.; Killian, T. C.

    2009-06-01

    We report measurement of the inelastic and elastic collision rates for S88r atoms in the (5s5p)P30 state in a crossed-beam optical dipole trap. Since the (5s5p)P30 state is the lowest level of the triplet manifold, large loss rates indicate the importance of principle-quantum-number-changing collisions at short range. We also provide an estimate of the collisional loss rates for the (5s5p)P32 state. Large loss-rate coefficients for both states indicate that evaporative cooling toward quantum degeneracy in these systems is unlikely to be successful.

  19. Successful triplet pregnancy in an African with pure gonadal dysgenesis:A plus for assisted reproduction

    Institute of Scientific and Technical Information of China (English)

    Aziken M; Osaikhuwuomwan J; Osemwenkha A; Iribhogbe O; Orhue A

    2015-01-01

    Gonadal dysgenesis represents a congenital developmental disorder of the reproductive system, with its main gynaecologic manifestations being amenorrhea and infertility. We present a unique case of pure gonadal dysgenesis in an ‘about to be’ married lady resident in a society where high premium and success in marriage is dependent on childbirth. With astute evaluation and counseling, assisted reproductive technology (ART) was safely and successfully used in this case with eventual triplet pregnancy and delivery. Our index experience shows that situations with compromised fertility the availability and access to ART aids effective treatment planning and births a re-invigorated hope for family life.

  20. Quenching behaviour of quadrupole model magnets for the LHC inner triplets at Fermilab

    CERN Document Server

    Andreev, N; Bauer, P; Bossert, R; Brandt, J; Chichili, D R; Carson, J; Di Marco, J; Fehér, S; Glass, H; Kerby, J S; Lamm, M J; Makarov, A A; Nobrega, A; Novitski, I; Ogitsu, T; Orris, D; Ozelis, J P; Rabehl, Roger Jon; Robotham, W; Sabbi, G L; Schlabach, P; Sylvester, C D; Strait, J B; Tartaglia, M; Tompkins, J C; Yadav, S; Zlobin, A V; Caspi, S; McInturff, A D; Scanlan, R M; Ghosh, A

    2000-01-01

    The US-LHC Accelerator Project is responsible for the design and production of inner triplet high gradient quadrupoles for installation in the LHC Interaction Region. The quadrupoles are required to deliver a nominal field gradient of 215 T/m in a 70 mm bore, and operate in superfluid helium. As part of the magnet development program, a series of 2 m model magnets have been built and tested at Fermilab, with each magnet being tested over several thermal cycles. This paper summarizes the quench performance and analysis of the model magnets tested, including quench training, and the ramp rate and temperature of the magnet quench current. (7 refs).

  1. Detection of Ca II absorption triplet in a circumnuclear H II region of NGC 3310

    International Nuclear Information System (INIS)

    We have obtained long slit spectrophotometry across NGC 3310, a luminous galaxy with circumnuclear bursts of star formation, covering the spectral range from λ3650 to 9700 A. In one giant star-forming region, the near-IR Ca II absorption lines (a signature of young supergiants) was detected with a strength similar to that of the nuclear region. This is, to our knowledge, the first detection of the IR Ca II triplet in an extragalactic giant H II region and confirms theoretical predictions that, after some 4 Myr, red supergiants should appear in bursts of star formation. (author)

  2. Singlet-triplet gaps in substituted carbenes predicted from block-correlated coupled cluster method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The block correlated coupled cluster (BCCC) method, with the complete active-space self-consistent-field (CASSCF) reference function, has been applied to investigating the singlet-triplet gaps in several substituted carbenes including four halocarbenes (CHCl, CF2, CCl2, and CBr2) and two hydroxycar-benes (CHOH and C(OH)2). A comparison of our results with the experimental data and other theoretical estimates shows that the present approach can provide quantitative descriptions for all the studied carbenes. It is demonstrated that the CAS-BCCC method is a promising theoretical tool for calculating the electronic structures of diradicals.

  3. Successful triplet pregnancy in an African with pure gonadal dysgenesis: A plus for assisted reproduction

    Directory of Open Access Journals (Sweden)

    M Aziken

    2015-06-01

    Full Text Available Gonadal dysgenesis represents a congenital developmental disorder of the reproductive system, with its main gynaecologic manifestations being amenorrhea and infertility. We present a unique case of pure gonadal dysgenesis in an ‘about to be’ married lady resident in a society where high premium and success in marriage is dependent on childbirth. With astute evaluation and counseling, assisted reproductive technology (ART was safely and successfully used in this case with eventual triplet pregnancy and delivery. Our index experience shows that situations with compromised fertility the availability and access to ART aids effective treatment planning and births a re-invigorated hope for family life.

  4. Rogue wave triplets in an ion-beam dusty plasma with superthermal electrons and negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Shimin, E-mail: gsm861@126.com [School of Mathematics and Statistics, Xi' an Jiaotong University, Xi' an, 710049 (China); Mei, Liquan, E-mail: lqmei@mail.xjtu.edu.cn [School of Mathematics and Statistics, Xi' an Jiaotong University, Xi' an, 710049 (China); Department of Chemical and Petroleum Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta, T2N 1N4 (Canada); Shi, Weijuan [College of Mathematics and Information Science, Shaanxi Normal University, Xi' an, 710062 (China)

    2013-11-01

    A new dust ion-acoustic wave structure called ‘Rogue wave triplets’ is investigated in an unmagnetized plasma consisting of stationary negatively charged dust grains, charged positive and negative ions, and electrons obeying kappa distribution, which is penetrated by an ion beam. The reductive perturbation theory is used to derive the nonlinear Schrödinger equation governing the dynamics as well as the modulation of wave packets. The rogue wave triplets which are composed of three separate Peregrine breathers can be generated in the modulation instability region. It has been suggested that a laboratory experiment be performed to test the theory presented here.

  5. Catalogues of isolated galaxies, isolated pairs, and isolated triplets in the local Universe

    Science.gov (United States)

    Argudo-Fernández, M.; Verley, S.; Bergond, G.; Duarte Puertas, S.; Ramos Carmona, E.; Sabater, J.; Fernández Lorenzo, M.; Espada, D.; Sulentic, J.; Ruiz, J. E.; Leon, S.

    2015-06-01

    Context. The construction of catalogues of galaxies and the a posteriori study of galaxy properties in relation to their environment have been hampered by scarce redshift information. The new 3-dimensional (3D) surveys permit small, faint, physically bound satellites to be distinguished from a background-projected galaxy population, giving a more comprehensive 3D picture of the surroundings. Aims: We aim to provide representative samples of isolated galaxies, isolated pairs, and isolated triplets for testing galaxy evolution and secular processes in low density regions of the local Universe, as well as to characterise their local and large-scale environments. Methods: We used spectroscopic data from the tenth data release of the Sloan Digital Sky Survey (SDSS-DR10) to automatically and homogeneously compile catalogues of 3702 isolated galaxies, 1240 isolated pairs, and 315 isolated triplets in the local Universe (z ≤ 0.080). To quantify the effects of their local and large-scale environments, we computed the projected density and the tidal strength for the brightest galaxy in each sample. Results: We find evidence of isolated pairs and isolated triplets that are physically bound at projected separations up to d ≤ 450 kpc with radial velocity difference Δν ≤ 160 km s-1, where the effect of the companion typically accounts for more than 98% of the total tidal strength affecting the central galaxy. For galaxies in the catalogues, we provide their positions, redshifts, and degrees of relation with their physical and large-scale environments. The catalogues are publicly available to the scientific community. Conclusions: For isolated galaxies, isolated pairs, and isolated triplets, there is no difference in their degree of interaction with the large-scale structure (up to 5 Mpc), which may suggest that they have a common origin in their formation and evolution. We find that most of them belong to the outer parts of filaments, walls, and clusters, and generally

  6. Finite-bias conductance anomalies at a singlet-triplet crossing

    DEFF Research Database (Denmark)

    Stevanato, Chiara; Leijnse, Martin Christian; Flensberg, Karsten;

    2012-01-01

    Quantum dots and single-molecule transistors may exhibit level crossings induced by tuning external parameters such as magnetic eld or gate voltage. For Coulomb blockaded devices, this shows up as an inelastic cotunneling threshold in the dierential conductance, which can be tuned to zero...... at the crossing. Here we show that, in addition, level crossings can give rise to a nearly vertical step-edge, ridge or even a Fano-like ridge-valley feature in the dierential conductance inside the relevant Coulomb diamond. We study a gate-tunable quasidegeneracy between singlet and triplet ground states...

  7. Higher-order recoil corrections for triplet states of the helium atom

    CERN Document Server

    Patkos, V; Pachucki, K

    2016-01-01

    Nuclear recoil corrections of order $\\alpha^6\\,m^2/M$ are calculated for the lowest-lying triplet states of the helium atom. It improves the theoretical prediction for the isotope shift of the $2^3S-2^3P$ transition energy and influences the determination of the ${}^3\\textrm{He}-{}^4\\textrm{He}$ nuclear charge radii difference. This calculation is a step forward on the way towards the direct determination of the charge radius of the helium nucleus from spectroscopic measurements.

  8. Hybrid spin and valley quantum computing with singlet-triplet qubits.

    Science.gov (United States)

    Rohling, Niklas; Russ, Maximilian; Burkard, Guido

    2014-10-24

    The valley degree of freedom in the electronic band structure of silicon, graphene, and other materials is often considered to be an obstacle for quantum computing (QC) based on electron spins in quantum dots. Here we show that control over the valley state opens new possibilities for quantum information processing. Combining qubits encoded in the singlet-triplet subspace of spin and valley states allows for universal QC using a universal two-qubit gate directly provided by the exchange interaction. We show how spin and valley qubits can be separated in order to allow for single-qubit rotations.

  9. A Three-loop Neutrino Mass Model with a Colored Triplet Scalar

    CERN Document Server

    Cheung, Kingman; Okada, Hiroshi

    2016-01-01

    We study a variation of the Krauss-Nasri-Trodden (KNT) model with a colored triplet scalar field and a colored singlet scalar field, in which we discuss the anomaly coming from $b\\to s\\mu\\bar\\mu$, fitting to the muon anomalous magnetic moment and the relic density of the Majorana-type dark matter candidate, as well as satisfying various constraints such as lepton-flavor violations and flavor-changing neutral currents. Also, we discuss the direct constraints from the collider searches and the possibilities of detecting the new fields at the LHC.

  10. Excited complexes in oxidation-reduction photoreactions of pigments. I. Spectral detection of triplet state exciplex in the chlorophyll oxidation reaction.

    Science.gov (United States)

    Andreeva, N E; Chibisov, A K

    1976-01-01

    Photooxidation of chlorophyll "a" with p-benzoquinone in toluene and dioxane is studied by the method of flash photolysis. It is shown that in nonpolar medium the triplet exiplex is the product of this reaction. The experiments on competitive quenching of chlorophyll triplet state with naphthacene prove the diffusion mechanism of exiplex formation. The spectrum of triplet-triplet absorption of the exiplex is presented and the rate constant of intercombination degradation equalling 1.103 sec(-1) is measured. Possible structure of the exiplex is discussed. PMID:1252529

  11. Theoretical rationalization of the singlet-triplet gap in OLEDs materials: impact of charge-transfer character.

    Science.gov (United States)

    Moral, M; Muccioli, L; Son, W-J; Olivier, Y; Sancho-García, J C

    2015-01-13

    New materials for OLED applications with low singlet-triplet energy splitting have been recently synthesized in order to allow for the conversion of triplet into singlet excitons (emitting light) via a Thermally Activated Delayed Fluorescence (TADF) process, which involves excited-states with a non-negligible amount of Charge-Transfer (CT). The accurate modeling of these states with Time-Dependent Density Functional Theory (TD-DFT), the most used method so far because of the favorable trade-off between accuracy and computational cost, is however particularly challenging. We carefully address this issue here by considering materials with small (high) singlet-triplet gap acting as emitter (host) in OLEDs and by comparing the accuracy of TD-DFT and the corresponding Tamm-Dancoff Approximation (TDA), which is found to greatly reduce error bars with respect to experiments thanks to better estimates for the lowest singlet-triplet transition. Finally, we quantitatively correlate the singlet-triplet splitting values with the extent of CT, using for it a simple metric extracted from calculations with double-hybrid functionals, that might be applied in further molecular engineering studies. PMID:26574215

  12. Singlet and triplet excited states and intersystem crossing in free-base porphyrin: TDDFT and DFT/MRCI study.

    Science.gov (United States)

    Perun, Serhiy; Tatchen, Jörg; Marian, Christel M

    2008-02-01

    Extensive time-dependent DFT (TDDFT) and DFT/multireference configuration interaction (MRCI) calculations are performed on the singlet and triplet excited states of free-base porphyrin, with emphasis on intersystem crossing processes. The equilibrium geometries, as well as the vertical and adiabatic excitation energies of the lowest singlet and triplet excited states are determined. Single and double proton-transfer reactions in the first excited singlet state are explored. Harmonic vibrational frequencies are calculated at the equilibrium geometries of the ground state and of the lowest singlet and triplet excited states. Furthermore, spin-orbit coupling matrix elements of the lowest singlet and triplet states and their numerical derivatives with respect to nuclear displacements are computed. It is shown that opening of an unprotonated pyrrole ring as well as excited-state single and double proton transfer inside the porphyrin cavity lead to crossings of the potential energy curves of the lowest singlet and triplet excited states. It is also found that displacements along out-of-plane normal modes of the first excited singlet state cause a significant increase of the , , and spin-orbit coupling matrix elements. These phenomena lead to efficient radiationless deactivation of the lowest excited states of free-base porphyrin via intercombination conversion. In particular, the S1-->T1 population transfer is found to proceed at a rate of approximately 10(7) s(-1) in the isolated molecule. PMID:18189251

  13. Some carcinogenic polycyclic aromatic hydrocarbons by photoacoustic spectroscopy

    Science.gov (United States)

    Garg, R. K.; Kumar, Pardeep; Ram, R. S.; Zaidi, Zahid H.

    1999-12-01

    Polycyclic aromatic hydrocarbons (PAHs) have attracted spectroscopists, astrophysicts and environmentalist because of their importance in our day to day life. It is well known that epoxides are produced during the metabolism of PAHs and have the requisite chemical reactivity to qualify them for the role as an ultimate carcinogenic form of PAHs. Several carcinogenic PAHs such as 3.4-benzopyrene, 1.2,3.4-dibenzopyrene, 3.4,9.10- dibenzopyrene etc. are found to be present in tobacco smoke and among air pollutants. Although PAH molecules are being studied for last several years by using conventional spectroscopy but no systematic attempt has been made to study non-radiative transitions. In our laboratory, we have studied many PAH molecules by a non-destructive technique with unique capability and sensitivity, known as Photoacoustic (PA) spectroscopy. PA spectroscopy is an analytical and research tool to get information about non-radiative transitions and singlet-triplet electronic transitions, where the conventional spectroscopic technique fails. The study of electronic transitions of some carcinogenic molecules are reported using PA and optical absorption spectra in boric acid glass in the region 250 - 400 nm. The electronic transitions of these molecules observed experimentally, have been interpreted using the optimized geometries and CNDO/S-CI method. A good agreement is found between the experimental and calculated results. Assignments of observed electronic transitions are made on the basis of singlet-triplet electronic transitions. Vibrations attached to these electronic transitions are attributed to the ground state vibrational modes.

  14. The magnetic field configuration of a solar prominence inferred from spectropolarimetric observations in the He I 10830 A triplet

    CERN Document Server

    Suárez, David Orozco; Bueno, Javier Trujillo

    2014-01-01

    Context: The determination of the magnetic field vector in quiescent solar prominences is possible by interpreting the Hanle and Zeeman effects in spectral lines. However, observational measurements are scarce and lack high spatial resolution. Aims: To determine the magnetic field vector configuration along a quiescent solar prominence by interpreting spectropolarimetric measurements in the He I 1083.0 nm triplet obtained with the Tenerife Infrared Polarimeter installed at the German Vacuum Tower Telescope of the Observatorio del Teide. Methods. The He I 1083.0 nm triplet Stokes profiles are analyzed with an inversion code that takes into account the physics responsible of the polarization signals in this triplet. The results are put into a solar context with the help of extreme ultraviolet observations taken with the Solar Dynamic Observatory and the Solar Terrestrial Relations Observatory satellites. Results: For the most probable magnetic field vector configuration, the analysis depicts a mean field streng...

  15. Implications of a Electroweak Triplet Scalar Leptoquark on the Ultra-High Energy Neutrino Events at IceCube

    CERN Document Server

    Mileo, Nicolas; Szynkman, Alejandro

    2016-01-01

    We study the production of scalar leptoquarks at IceCube, in particular, a particle transforming as a triplet under the weak interaction. The existence of electroweak-triplet scalars is highly motivated by models of grand unification and also within radiative seesaw models for neutrino mass generation. In our framework, we extend the Standard Model by a single colored electroweak-triplet scalar leptoquark and analyze its implications on the excess of ultra-high energy neutrino events observed by the IceCube collaboration. We consider only couplings between the leptoquark to first generation leptons and quarks and carry out a statistical analysis to determine the parameters that best describe the IceCube data as well as set $95\\%$ CL upper bounds. We analyze whether this study is still consistent with most up-to-date LHC data and various low energy observables.

  16. Triplet formation in fullerene multi-adduct blends for organic solar cells and its influence on device performance

    Energy Technology Data Exchange (ETDEWEB)

    Dyer-Smith, Clare [Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ (United Kingdom); Grantham Institute for Climate Change, Imperial College London, South Kensington Campus, London, SW7 2AZ (United Kingdom); Reynolds, Luke X. [Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ (United Kingdom); Grantham Institute for Climate Change, Imperial College London, South Kensington Campus, London, SW7 2AZ (United Kingdom); Bruno, Annalisa; Haque, Saif A. [Department of Chemistry, Imperial College London, South Kensington Campus, London, SW7 2AZ (United Kingdom); Bradley, Donal D.C.; Nelson, Jenny [Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2010-08-23

    In organic solar cells, high open circuit voltages may be obtained by choosing materials with a high offset between the donor highest occupied molecular orbital (HOMO) and acceptor lowest unoccupied molecular orbital (LUMO). However, increasing this energy offset can also lead to photophysical processes that compete with charge separation. In this paper the formation of triplet states is addressed in blends of polyfluorene polymers with a series of PCBM multi-adducts. Specifically, it is demonstrated that the formation of such triplets occurs when the offset energy between donor ionization potential and acceptor electron affinity is {proportional_to}1.6 eV or greater. Spectroscopic measurements support a mechanism of resonance energy transfer for triplet formation, influenced by the energy levels of the materials, but also demonstrate that the competition between processes at the donor-acceptor interface is strongly influenced by morphology. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  17. J-state interference signatures in the Second Solar Spectrum: Modeling the Cr I triplet at 5204-5208 A

    CERN Document Server

    Smitha, H N; Stenflo, J O; Bianda, M; Sampoorna, M; Ramelli, R; Anusha, L S

    2012-01-01

    The scattering polarization in the solar spectrum is traditionally modeled with each spectral line treated separately, but this is generally inadequate for multiplets where J-state interference plays a significant role. Through simultaneous observations of all the 3 lines of a Cr I triplet, combined with realistic radiative transfer modeling of the data, we show that it is necessary to include J-state interference consistently when modeling lines with partially interacting fine structure components. Polarized line formation theory that includes J-state interference effects together with partial frequency redistribution for a two-term atom is used to model the observations. Collisional frequency redistribution is also accounted for. We show that the resonance polarization in the Cr I triplet is strongly affected by the partial frequency redistribution effects in the line core and near wing peaks. The Cr I triplet is quite sensitive to the temperature structure of the photospheric layers. Our complete frequency...

  18. Forbidden Electronic Transitions between the Singlet Ground State and the Triplet Excited State of Pt(II) Complexes.

    Science.gov (United States)

    Zheng, Greg Y.; Rillema, D. Paul; DePriest, Jeff; Woods, Clifton

    1998-07-13

    Direct access to the triplet emitting state from the ground state is observed for Pt(II) complexes containing heterocyclic (CwedgeC', CwedgeN, NwedgeN') and bis(diphenylphosphino)alkane (PwedgeP') ligands. Extinction coefficients for such transitions are in the range 4-25 M(-)(1) cm(-)(1). Emission quantum yields resulting from singlet-to-triplet excitation are as high as 61-77 times the emission quantum yields resulting from singlet-to-singlet excitation at 296 K. The intersystem crossing quantum yield from the singlet excited state to triplet emitting state is lower than 2% at 296 K but is greatly enhanced at 77 K. The forbidden electronic transition observed for Pt(II) complexes is attributed to result from spin-orbit coupling due to the presence of Pt(II) in the skeleton structure. The importance of excitation spectra on the computation of emission quantum yields is discussed.

  19. Third-order spontaneous parametric down-conversion in thin optical fibers as a photon-triplet source

    Energy Technology Data Exchange (ETDEWEB)

    Corona, Maria [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, apdo. postal 70-543, DF 04510 Mexico City (Mexico); Departamento de Optica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Apartado Postal 2732, BC 22860 Ensenada (Mexico); Garay-Palmett, Karina; U' Ren, Alfred B. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, apdo. postal 70-543, DF 04510 Mexico City (Mexico)

    2011-09-15

    We study the third-order spontaneous parametric down-conversion (TOSPDC) process, as a means to generate entangled photon triplets. Specifically, we consider thin optical fibers as the nonlinear medium to be used as the basis for TOSPDC in configurations where phase matching is attained through the use of more than one fiber transverse modes. Our analysis in this paper, which follows from our earlier paper [Opt. Lett. 36, 190-192 (2011)], aims to supply experimentalists with the details required in order to design a TOSPDC photon-triplet source. Specifically, our analysis focuses on the photon triplet state, on the rate of emission, and on the TOSPDC phase-matching characteristics for the cases of frequency-degenerate and frequency nondegenerate TOSPDC.

  20. Efficient Hybrid White Organic Light-Emitting Diodes for Application of Triplet Harvesting with Simple Structure

    CERN Document Server

    Hwang, Kyo Min; Lee, Sungkyu; Yoo, Han Kyu; Baek, Hyun Jung; Kim, Jwajin; Yoon, Seung Soo; Kim, Young Kwan

    2016-01-01

    In this study, we fabricated hybrid white organic light-emitting diodes (WOLEDs) based on triplet harvesting with simple structure. All the hole transporting material and host in emitting layer (EML) of devices were utilized with same material by using N,N'-di-1-naphthalenyl-N,N'-diphenyl-[1,1':4',1":4",1"'-quaterphenyl]-4,4"'-diamine (4P-NPD) which were known to be blue fluorescent material. Simple hybrid WOLEDs were fabricated three color with blue fluorescent and green, red phosphorescent materials. We was investigated the effect of triplet harvesting (TH) by exciton generation zone on simple hybrid WOLEDs. Characteristic of simple hybrid WOLEDs were dominant hole mobility, therefore exciton generation zone was expected in EML. Additionally, we was optimization thickness of hole transporting layer and electron transporting layer was fabricated a simple hybrid WOLEDs. Simple hybrid WOLED exhibits maximum luminous efficiency of 29.3 cd/A and maximum external quantum efficiency of 11.2%. Commission Internatio...

  1. Gas-phase hydrolysis of triplet SO2: A possible direct route to atmospheric acid formation.

    Science.gov (United States)

    Donaldson, D James; Kroll, Jay A; Vaida, Veronica

    2016-01-01

    Sulfur chemistry is of great interest to the atmospheric chemistry of several planets. In the presence of water, oxidized sulfur can lead to new particle formation, influencing climate in significant ways. Observations of sulfur compounds in planetary atmospheres when compared with model results suggest that there are missing chemical mechanisms. Here we propose a novel mechanism for the formation of sulfurous acid, which may act as a seed for new particle formation. In this proposed mechanism, the lowest triplet state of SO2 ((3)B1), which may be accessed by near-UV solar excitation of SO2 to its excited (1)B1 state followed by rapid intersystem crossing, reacts directly with water to form H2SO3 in the gas phase. For ground state SO2, this reaction is endothermic and has a very high activation barrier; our quantum chemical calculations point to a facile reaction being possible in the triplet state of SO2. This hygroscopic H2SO3 molecule may act as a condensation nucleus for water, giving rise to facile new particle formation (NPF). PMID:27417675

  2. Rectification and Robust Matching Using Oriented Image Triplets for Minimally Invasive Surgery

    Science.gov (United States)

    Conen, N.; Jepping, C.; Luhmann, T.; Maas, H.-G.

    2016-06-01

    Stereo endoscopes for minimally invasive surgery have been available on the market for several years and are well established in some areas. In practice, they offer a stereoscopic view to the surgeon but are not yet intended for 3D measurements. However, using current knowledge about the camera system and the difficult conditions in object space, it is possible to reconstruct a highly accurate surface model of the current endoscopic view. In particular for medical interventions, a highly reliable point cloud and real-time computation are required. To obtain good reliability, a miniaturised trinocular camera system is introduced that reduces the amount of outliers. To reduce computation time, an approach for generation of rectified image triplets and their corresponding interior and exterior camera parameters has been developed. With these modified and parameterised images it is possible to directly process 3D measurements in object space. Accordingly, an efficient semi-global optimisation is implemented by the authors. In this paper the special camera system, the rectification approach and the applied methodology of matching in rectified image triplets are explained. Finally, first results are presented. In conclusion, the trinocular camera system provides more reliable point clouds than a binocular one, especially for areas with repetitive or poor texture. Currently, the benefit of the third camera is not as great as desired.

  3. Expressions of excited states by triplet dimers in heisenberg antiferromagnetic ladders. Analysis of magnetic Raman spectra

    Energy Technology Data Exchange (ETDEWEB)

    Natsume, Yuhei; Tada, Shinichiro; Suzuki, Toshihiko [Chiba Univ., Graduate School of Science and Technology, Chiba (Japan)

    2002-06-01

    Characteristic properties of excited states in antiferromagnetic ladder systems with spin-1/2 are investigated in relation with the theoretical analysis of the quite asymmetric shape of the peak for twice the spin gap {delta}{sub g} in magnetic Raman spectra. Here, the structure of exchange-scattering spectra are reproduced by the numerical calculation for the finite Heisenberg ladder, in which legs with antiferromagnetic bond J{sub c} is connected by rungs with antiferromagnetic bond J{sub r}. The singlet ground state in this system can be expressed as the ordering of singlet dimers on rungs in the ladder for J{sub c}/J{sub r} {yields} +0. In fact, the value of 0.1 is adopted to be the ratio of J{sub c}/J{sub r} in order to discuss the experimental work of the magnetic Raman spectra for the ladder of V{sup 4+} ions in the oxide compound CaV{sub 2}O{sub 5} reported in Konstantinovic et al., Phys. Rev. B61 (2000), 15185. As for this peak of 2{delta}{sub g}, quite an asymmetric observed shape is explained by the present calculation. According to the analysis of spectra, we discuss the expression of excited states by triplet dimers on rungs: The dominant contribution of the pair of triplet dimers on adjacent rungs to the corresponding state for 2{delta}{sub g} peak is pointed out. (author)

  4. Triplet generation and upper critical field in superconducting spin valves based on CrO2

    Science.gov (United States)

    Voltan, S.; Singh, A.; Aarts, J.

    2016-08-01

    It has been recently reported that a superconducting triplet spin valve (TSV) based on the half-metallic CrO2 can show "colossal" variations of the critical temperature, up to more than 1 K. This can be achieved when the magnetic noncollinearity between the mixer (F1) and the drainage ferromagnetic layer (F) is maximized. In this work we investigate further such TSV devices looking at two aspects: first, we present the dependence of the TSV effect on the thickness of the mixer layer; second, we look at the perpendicular upper critical field Hc 2 ⊥ as a function of the temperature. The thickness dependence, which is nonmonotonic as expected, represents a further proof that the effect is due to the generation of equal-spin triplet Cooper pairs, while what we observe for the Hc 2 ⊥ versus T curves is an interesting and peculiar behavior: there is a clear deviation from the universal linear dependence and the average slope is suppressed much more than what can be described with the formalism used for conventional proximized structures.

  5. Photosensitizing and Inhibitory Effects of Ozonated Dissolved Organic Matter on Triplet-Induced Contaminant Transformation.

    Science.gov (United States)

    Wenk, Jannis; Aeschbacher, Michael; Sander, Michael; von Gunten, Urs; Canonica, Silvio

    2015-07-21

    Dissolved organic matter (DOM) is both a promoter and an inhibitor of triplet-induced organic contaminant oxidation. This dual role was systematically investigated through photochemical experiments with three types of DOM of terrestrial and aquatic origins that were preoxidized to varying extents by ozonation. The inhibitory effect of DOM was assessed by determining the 4-carboxybenzophenone photosensitized transformation rate constants of two sulfonamide antibiotics (sulfamethoxazole and sulfadiazine) in the presence of untreated or preoxidized DOM. The inhibitory effect decreased with the increasing extent of DOM preoxidation, and it was correlated to the loss of phenolic antioxidant moieties, as quantified electrochemically, and to the loss of DOM ultraviolet absorbance. The triplet photosensitizing ability of preoxidized DOM was determined using the conversion of the probe compound 2,4,6-trimethylphenol (TMP), which is unaffected by DOM inhibition effects. The DOM photosensitized transformation rate constants of TMP decreased with increasing DOM preoxidation and were correlated to the concomitant loss of chromophores (i.e., photosensitizing moieties). The combined effects of DOM preoxidation on the inhibiting and photosensitizing properties were assessed by phototransformation experiments of the sulfonamides in DOM-containing solutions. At low extents of DOM preoxidation, the sulfonamide phototransformation rate constants remained either unchanged or slightly increased, indicating that the removal of antioxidant moieties had larger effects than the loss of photosensitizing moieties. At higher extents of DOM preoxidation, transformation rates declined, mainly reflecting the destruction of photosensitizing moieties. PMID:26091366

  6. Dark matter versus h→γγ and h→γZ with supersymmetric triplets

    International Nuclear Information System (INIS)

    The Triplet extension of the MSSM (TMSSM) alleviates the little hierarchy problem and provides a significant enhancement of the loop-induced diphoton rate of the lightest CP-even Higgs h. In this paper we pursue the analysis of the TMSSM Higgs phenomenology by computing for the first time the h→Zγ decay. Interestingly we find that the rates of loop-induced decays are correlated and their signal strengths can rise up to 40%-60% depending on the channel. We furthermore study the dark matter phenomenology of the TMSSM. The lightest neutralino is a good dark matter candidate in two regions. The first one is related to the Higgs and Z resonances and the LSP is mostly Bino. The second one is achieved for a mass larger than 90 GeV and the LSP behaves as the well-tempered neutralino. An advantage of the triplet contribution is that the well-tempered neutralino can be a Bino-Triplino mixture, relieving the problem of achieving M2∝M1 in unified scenarios. The dark matter constraints strongly affect the Higgs phenomenology, reducing the potential enhancements of the diphoton and of the Zγ channels by 20% at most. These enhancements are however larger than the MSSM ones. In the near future, complementarity of dark matter direct searches and collider experiments will be crucial to probe most of the parameter space where the neutralino is the dark matter candidate.

  7. A CP-violating phase in a two Higgs triplet scenario : some phenomenological implications

    CERN Document Server

    Chaudhuri, Avinanda

    2016-01-01

    We consider a scenario where, along with the usual Higgs doublet, two scalar triplets are present. The extension of the triplet sector is required for the Type~II mechanism for the generation of neutrino masses, if this mechanism has to generate a neutrino mass matrix with two-zero texture. One CP-violating phase has been retained in the scalar potential of the model, and all parameters have been chosen consistently with the observed neutrino mass and mixing patterns. We find that a large phase ($\\gtrsim 60^{\\circ}$) splits the two doubly-charged scalar mass eigenstates wider apart, so that the decay $H_1^{++} \\rightarrow H_2^{++} h$ is dominant (with h being the $125$ GeV scalar). We identify a set of benchmark points where this decay dominates. This is complementary to the situation, reported in our earlier work, where the heavier doubly-charged scalar decays as $H_1^{++} \\rightarrow H_2^+ W^+$. We point out the rather spectacular signal, ensuing from $H_1^{++} \\rightarrow H_2^{++} h$, in the form of Higgs ...

  8. Elastic Scattering between Ultracold 23Na and 85Rb Atoms in the Triplet State

    Institute of Scientific and Technical Information of China (English)

    HU Qiu-Bo; ZHANG Yong-Sheng; SUN Jin-Feng; YU Ke

    2011-01-01

    @@ The elastic scattering Properties between ultracold 23Na and 85Rd atoms for the triplet state(a3∑u+ )are researched.The s-wave scattering lengts of 23Na and 85Rb are calculate by the Numerov ana semtc asstc method with two kinds of interatomic potentials, which are the interpolation potential and Lennard-Jones potential(LJ12,6)by the same phase 4φ Shape resonances appear clearly in the l= 5 partial waves for the a- Lu state.Moreover, the s-wave scattering cross section, total cross section and energy positions of shape resonances are also discussed.%The elastic scattering properties between ultracold 23Na and 85 Rb atoms for the triplet state (a3Σu+ ) are researched. The s-wave scattering lengths of 23Na and 85Rb are calculated by the Numerov and semiclassical method with two kinds of interatomic potentials, which are the interpolation potential and Lennard-Jones potential (LJ12,6) by the same phase φ. Shape resonances appear clearly in the l= 5 partial waves for the a3 Σu+state. Moreover, the s-wave scattering cross section, total cross section and energy positions of shape resonances are also discussed.

  9. The Chemical Enrichment History of the Fornax Dwarf Spheroidal Galaxy from the Infrared Calcium Triplet

    CERN Document Server

    Pont, F; Gallart, C; Hardy, E; Winnick, R A; Pont, Frederic; Zinn, Robert; Gallart, Carme; Hardy, Eduardo; Winnick, Rebeccah

    2004-01-01

    Near infrared spectra were obtained for 117 red giants in the Fornax dwarf spheroidal galaxy with the FORS1 spectrograph on the VLT, in order to study the metallicity distribution of the stars and to lift the age-metallicity degeneracy of the red giant branch (RGB) in the color-magnitude diagram (CMD). Metallicities are derived from the equivalent widths of the infrared Calcium triplet lines at 8498, 8542, and 8662 A, calibrated with data from globular clusters, the open cluster M67 and the LMC. For a substantial portion of the sample, the strength of the Calcium triplet is unexpectedly high, clearly indicating that the main stellar population of Fornax is significantly more metal-rich than could be inferred from the position of its RGB in the CMD. We show that the relative narrowness of the RGB in Fornax is caused by the superposition of stars of very different ages and metallicities. The metallicity distribution in Fornax is centered at [Fe/H]= -0.9, with a metal-poor tail extending to [Fe/H] ~= -2. While t...

  10. Preliminary Design of the HiLumi-LHC Triplet Area Beam Screen

    CERN Document Server

    Kersevan, R; Kos, N

    2014-01-01

    The so-called beam screen (BS) is a proven solution for intercepting the thermal loads caused by the circulating beams in the cryogenically-cooled sections of the LHC and minimizing dynamic vacuum effects [1]. The new triplet area foreseen for the HiLumi-LHC (HL-LHC) machine upgrade [2] has the additional feature of needing internal tungsten shields to reduce the amount of collision debris which is deflected by the high-gradient triplet magnets towards the superconducting magnets' cold masses and coils. The very aggressive optics design, based on large beam separations, calls for a maximum of physical space to remain available to the counter rotating beams in the common BS. This places severe constraints to the fabrication and installation tolerances of the BS itself, in addition to affecting the design and routing of the cryogenic lines in the area. The latest version of the BS design will be shown and discussed, together with future plans for testing materials, fabrication procedures, and installation.

  11. Anion photoelectron spectroscopy of radicals and clusters

    Energy Technology Data Exchange (ETDEWEB)

    Travis, Taylor R.

    1999-12-16

    Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

  12. Nuclear spectroscopy

    CERN Document Server

    Ajzenberg-Selove, Fay

    1960-01-01

    Nuclear Spectroscopy, Part A deals with the experimental and theoretical techniques involved in nuclear spectroscopy.This book discusses the interactions of charged particles with matter, gaseous ionization detectors, and particular mass attenuation coefficients. The magnetic gamma-ray spectrometers for photo or internal-conversion electrons, general characteristics of cross-section variation with energy, and measurement of fast neutron spectra are also elaborated. This text likewise covers the elastic scattering of photons by nuclei and measurement of widths of gamma-radiating levels.This pub

  13. Optogalvanic spectroscopy

    International Nuclear Information System (INIS)

    Laser induced optogalvanic spectroscopy in a hollow cathode-produced plasma has been used to resolve the isotopic structure of some absorption lines in uranium. We have shown that the optogalvanic signal associated with any isotope can be related to the concentration of that isotope in a multi-isotopic sample. From the results we have obtained, optogalvanic spectroscopy of sputtered samples appears to be an interesting approach to the isotopic analysis of both natural and enriched uranium and could easily be applied to the analysis of other fissile elements, such as the plutonium isotopes

  14. Helium-like triplet density diagnostics: Applications to CHANDRA--LETGS X-ray observations of Capella and Procyon

    OpenAIRE

    Ness, J. U.; Mewe, R.; Schmitt, J. H. M. M.; Raassen, A. J. J.; Porquet, D.; Kaastra, J. S.; Van Der Meer, R.L.J.; Burwitz, V.; Predehl, P.

    2000-01-01

    Electron density diagnostics based on the triplets of Helium-like CV, NVI, and OVII are applied to the X-ray spectra of Capella and Procyon measured with the Low Energy Transmission Grating Spectrometer (LETGS) on board the Chandra X-ray Observatory. New theoretical models for the calculation of the line ratios between the forbidden (f), intercombination (i), and the resonance (r) lines of the helium-like triplets are used. The derived densities are quite typical of densities found in the sol...

  15. Bioimpedance Spectroscopy

    DEFF Research Database (Denmark)

    Klösgen, Beate; Rümenapp, Christine; Gleich, Bernhard

    2011-01-01

    causes relaxation processes with characteristic contributions to the frequency-dependent complex dielectric constant. These dipolar relaxations were initially described by Debye (Polare Molekeln 1929). They are the basis of impedance spectroscopy (K’Owino and Sadik Electroanalysis 17(23):2101–2113, 2005...

  16. PLASMA SPECTROSCOPY

    NARCIS (Netherlands)

    Jaspers, R. J. E.

    2010-01-01

    A brief introduction into the spectroscopy of fusion plasmas is presented. Basic principles of the emission of ionic, atomic and molecular radiation is explained and a survey of the effects, which lead to the population of the respective excited levels, is given. Line radiation, continuum radiation,

  17. Optimal first-line chemotherapeutic treatment in patients with locally advanced or metastatic esophagogastric carcinoma : triplet versus doublet chemotherapy: a systematic literature review and meta-analysis

    NARCIS (Netherlands)

    Mohammad, N Haj; ter Veer, E; Ngai, L; Mali, R; van Oijen, M G H; van Laarhoven, H W M

    2015-01-01

    There is a debate whether triplet or doublet chemotherapy should be used as a first-line treatment in patients with advanced or metastatic esophagogastric cancer. Therefore, here we will review the available literature to assess the efficacy and safety of triplet versus doublet chemotherapy as a fir

  18. Optical Spectroscopy

    DEFF Research Database (Denmark)

    Thyrhaug, Erling

    containing systems using simple instrumentation and well-known and understood theoretical concepts. Overall it is attempted to achieve this goal by presenting five research projects that I have been involved in during my Ph.D. studies which collectively demonstrate some of the many possibilities of gaining...... containing systems and are characterized using techniques in optical spectroscopy. Of the standard techniques in optical spectroscopy, particular attention has been paid to those based on time-resolved measurements and polarization, which is reflected in the experiment design in the projects. Not all...... solution. In project 2 the intramolecular excited state association reaction between aniline and anthracene is characterized by both steady-state and time-resolved techniques, where the time resolved fluorescence measurements in particular allowed for the determination of the reaction rate constants...

  19. Transient photocurrent in molecular junctions: singlet switching on and triplet blocking.

    Science.gov (United States)

    Petrov, E G; Leonov, V O; Snitsarev, V

    2013-05-14

    The kinetic approach adapted to describe charge transmission in molecular junctions, is used for the analysis of the photocurrent under conditions of moderate light intensity of the photochromic molecule. In the framework of the HOMO-LUMO model for the single electron molecular states, the analytic expressions describing the temporary behavior of the transient and steady state sequential (hopping) as well as direct (tunnel) current components have been derived. The conditions at which the current components achieve their maximal values are indicated. It is shown that if the rates of charge transmission in the unbiased molecular diode are much lower than the intramolecular singlet-singlet excitation/de-excitation rate, and the threefold degenerated triplet excited state of the molecule behaves like a trap blocking the charge transmission, a possibility of a large peak-like transient switch-on photocurrent arises. PMID:23676066

  20. Empirical calibration of the near-IR Ca II triplet - III. Fitting functions

    CERN Document Server

    Cenarro, A J; Cardiel, N; Vazdekis, A; Peletier, R F

    2001-01-01

    Using a near-IR stellar library of 706 stars with a wide coverage of atmospheric parameters, we study the behaviour of the Ca II triplet strength in terms of effective temperature, surface gravity and metallicity. Empirical fitting functions for recently defined line-strength indices, namely CaT*, CaT and PaT, are provided. These functions can be easily implemented into stellar populations models to provide accurate predictions for integrated Ca II strengths. We also present a thorough study of the various error sources and their relation to the residuals of the derived fitting functions. Finally, the derived functional forms and the behaviour of the predicted Ca II are compared with those of previous works in the field.

  1. Measurements of Ca II Infrared Triplet Lines of Young Stellar Objects

    CERN Document Server

    Moto'oka, Keiko

    2015-01-01

    Equivalent widths and line widths of Ca II infrared triplet emission lines were measured in high-resolution optical spectra of 39 young stellar objects.We found that the equivalent widths of the emission lines decrease with stellar evolution. It has been often claimed that strong chromospheric activity is generated by a dynamo process caused by fast rotation of the photosphere. However, we found no clear correlation between the strength of the Ca II lines and the stellar rotation velocity. Instead, we found that the objects with high mass accretion rates had stronger Ca II emission lines. This correlation supports the turbulent chromosphere model or the magnetic accretion theory for classical T Tauri stars. We also noticed that the equivalent widths of Ca II lines of transitional disk objects are one-tenth of those of classical T Tauri stars, even if the masses of the circumstellar disks are comparable.

  2. On the doublet/triplet splitting and intermediate mass scales in locally supersymmetric SO(10)

    Science.gov (United States)

    Pulido, João

    1985-01-01

    In the light of the doublet/triplet splitting, the possibilities for an intermediate mass scale in locally supersymmetric SO(10) are analysed. It is found that the subgroup SU(4)c × SU(2)L × SU(2)R and more generally left-right symmetric models are unlikely to survive as intermediate symmetries since they imply too large values of the weak mixing angle. An alternative model using the subgroup SU(3)c × U(1)L × U(1)R is discussed. Requirements from global SUSY preservation impose an extra constraint and predictions for the grand unification and the intermediate masses are obtained at MX ~ 6 × 1015 GeV and MI ~ 1012 GeV. Address after March 1984: Centro de Fisica da Materia Condensada, Av. Prof. Gama Pinto, 2, 1699 Lisbon Codex, Portugal.

  3. SU(2)L-TRIPLET Dark Matter and Heat Anomaly in Cosmic Positron Experiment

    Science.gov (United States)

    Matsumoto, Shigeki; Hisano, Junji; Saito, Osamu; Senami, Masato

    2007-03-01

    Recently the HEAT collaboration has been reported the anomaly about the positron excess in the comic ray. The anomaly attracts attention because it may originate in the dark matter annihilation in the galactic halo. In this letter, I would like to address about the interesting fact that the SU(2)L-triplet dark matter can explain the anomaly with satisfying the present dark matter abundance observed by WMAP. When the mass of the dark matter is around 2 TeV, which is favored from the thermal relic abundance, the non-perturbation effect significantly enhances the annihilation cross section into positrons in the non-relativistic limit. We show that the effect enables us to account for the HEAT anomaly.

  4. Phototransformation of pesticides in prairie potholes: effect of dissolved organic matter in triplet-induced oxidation.

    Science.gov (United States)

    Karpuzcu, M Ekrem; McCabe, Andrew J; Arnold, William A

    2016-02-01

    Photochemical reactions involving a variety of photosensitizers contribute to the abiotic transformation of pesticides in prairie pothole lakes (PPLs). Despite the fact that triplet excited state dissolved organic matter (DOM) enhances phototransformation of pesticides by acting as a photosensitizer, it may also decrease the overall phototransformation rate through various mechanisms. In this study, the effect of DOM on the phototransformation of four commonly applied pesticides in four different PPL waters was investigated under simulated sunlight using photoexcited benzophenone-4-carboxylate as the oxidant with DOM serving as an anti-oxidant. For atrazine and mesotrione, a decrease in phototransformation rates was observed, while phototransformations of metolachlor and isoproturon were not affected by DOM inhibition. Phototransformation rates and the extent of inhibition/enhancement by DOM varied spatially and temporally across the wetlands studied. Characterization of DOM from the sites and different seasons suggested that the DOM type and variations in the DOM structure are important factors controlling phototransformation rates of pesticides in PPLs.

  5. Filter function formalism beyond pure dephasing and non-Markovian noise in singlet-triplet qubits

    Science.gov (United States)

    Barnes, Edwin; Rudner, Mark S.; Martins, Frederico; Malinowski, Filip K.; Marcus, Charles M.; Kuemmeth, Ferdinand

    2016-03-01

    The filter function formalism quantitatively describes the dephasing of a qubit by a bath that causes Gaussian fluctuations in the qubit energies with an arbitrary noise power spectrum. Here, we extend this formalism to account for more general types of noise that couple to the qubit through terms that do not commute with the qubit's bare Hamiltonian. Our approach applies to any power spectrum that generates slow noise fluctuations in the qubit's evolution. We demonstrate our formalism in the case of singlet-triplet qubits subject to both quasistatic nuclear noise and 1 /ωα charge noise and find good agreement with recent experimental findings. This comparison shows the efficacy of our approach in describing real systems and additionally highlights the challenges with distinguishing different types of noise in free induction decay experiments.

  6. Direct optical access to the triplet manifold of states in H2

    Science.gov (United States)

    Jungen, Ch.; Glass-Maujean, M.

    2016-03-01

    A number of unassigned lines in the absorption spectrum of diatomic hydrogen are attributed to nominally forbidden transitions from the ground state to the n f manifold of states (Rydberg electron with ℓ =3 orbital momentum). They appear via weak ℓ - mixing interactions leading to local level perturbations. Our analysis is based on multichannel quantum defect theory and uses known theoretical information from the literature. The upper levels of most of these transitions are known to give rise to molecular fluorescence, and they are shown to be singlet-triplet mixed. We conclude that the well-known metastable c 3Πu- state can be populated via one-photon absorption of uv photons followed by cascade emission 4 f →3 d →2 p .

  7. Spin supercurrent and phase-tunable triplet Cooper pairs via magnetic insulators

    Science.gov (United States)

    Gomperud, Ingvild; Linder, Jacob

    2015-07-01

    We demonstrate theoretically that a dissipationless spin current can flow a long distance through a diffusive normal metal by using superconductors interfaced with magnetic insulators. The magnitude of this spin supercurrent is controlled via the magnetization orientation of the magnetic insulators. The spin supercurrent obtained in this way is conserved in the normal metal just like the charge current and interestingly has a term that is independent of the superconducting phase difference. The quantum state of the system can be switched between 0 and π by reversing the insulators from a parallel to antiparallel configuration with an external field. We show that the spin current is carried through the normal metal by superconducting triplet (odd-frequency) correlations and that the superconducting phase difference can be used to enhance these, leaving clear spectroscopic fingerprints in the density of states.

  8. Conductivity estimates of spherical-particle suspensions based on triplet structure factors

    Science.gov (United States)

    Nguyen, Minh-Tan; Monchiet, Vincent; Bonnet, Guy; To, Quy-Dong

    2016-02-01

    In this paper, we present an estimation of the conductivity of composites constituted of identical spheres embedded in a host material. A family of polarization integral equations for the localization problem is constructed and the operator is then minimized to yield an optimal integral equation. As a result, the corresponding Neumann series converges with the fastest rate and can be used to estimate the effective conductivity. By combining this series and integral approximation, one can derive explicit expressions for the overall property using expansions in Fourier domain. For random hard-sphere systems, relations to structure factors and triplet structure factors have been made and Kirkwood superposition approximation is used to evaluate the effective conductivity, taking into account third-order correlations. This presents an original means to account for the statistical information up to third-order correlation when determining the effective properties of composite materials.

  9. Transient photocurrent in molecular junctions: singlet switching on and triplet blocking.

    Science.gov (United States)

    Petrov, E G; Leonov, V O; Snitsarev, V

    2013-05-14

    The kinetic approach adapted to describe charge transmission in molecular junctions, is used for the analysis of the photocurrent under conditions of moderate light intensity of the photochromic molecule. In the framework of the HOMO-LUMO model for the single electron molecular states, the analytic expressions describing the temporary behavior of the transient and steady state sequential (hopping) as well as direct (tunnel) current components have been derived. The conditions at which the current components achieve their maximal values are indicated. It is shown that if the rates of charge transmission in the unbiased molecular diode are much lower than the intramolecular singlet-singlet excitation/de-excitation rate, and the threefold degenerated triplet excited state of the molecule behaves like a trap blocking the charge transmission, a possibility of a large peak-like transient switch-on photocurrent arises.

  10. A novel SAR fusion image segmentation method based on triplet Markov field

    Science.gov (United States)

    Wang, Jiajing; Jiao, Shuhong; Sun, Zhenyu

    2015-03-01

    Markov random field (MRF) has been widely used in SAR image segmentation because of the advantage of directly modeling the posterior distribution and suppresses the speckle on the influence of the segmentation result. However, when the real SAR images are nonstationary images, the unsupervised segmentation results by MRF can be poor. The recent proposed triplet Markov field (TMF) model is well appropriate for nonstationary SAR image processing due to the introduction of an auxiliary field which reflects the nonstationarity. In addition, on account of the texture features of SAR image, a fusion image segmentation method is proposed by fusing the gray level image and texture feature image. The effectiveness of the proposed method in this paper is demonstrated by a synthesis SAR image and the real SAR images segmentation experiments, and it is better than the state-of-art methods.

  11. Singlet-triplet gaps in substituted carbenes predicted from block-correlated coupled cluster method

    Institute of Scientific and Technical Information of China (English)

    SHEN Jun; FANG Tao; LI Shuhua

    2008-01-01

    Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, ChinaThe block correlated coupled cluster (BCCC) method, with the complete active-space self-consistent-field (CASSCF) reference function, has been applied to investigating the singlet-triplet gaps in several substituted carbenes including four halocarbenes (CHCl, CF2, CCl2, and CBr2) and two hydroxycar-bones (CHOH and C(OH)2). A comparison of our results with the experimental data and other theoretical estimates shows that the present approach can provide quantitative descriptions for all the studied carbenes. It is demonstrated that the CAS-BCCC method is a promising theoretical tool for calculating the electronic structures of diradicals.

  12. 750-GeV Diphoton Resonance as the Singlet of Custodial Higgs Triplet Model

    CERN Document Server

    Chiang, Cheng-Wei

    2016-01-01

    The observation of diphoton excess around the mass of 750~GeV at the LHC motivates us to consider the singlet Higgs boson in the custodial Higgs triplet model as a good candidate. Based on an earlier study of comprehensive parameter scan for viable mass spectra, we show that the diphoton resonance data fall well within the allowed space. Moreover, we point out that a definite mass hierarchy emerges among the exotic Higgs bosons in the model. Further search channels for the singlet and those for the other exotic Higgs bosons in LHC Run-II are discussed. In particular, we present a simulation of distributions of two kinematic variables for the search of the doubly-charged Higgs boson.

  13. Collective modes of the order parameter in a triplet superfluid neutron liquid

    CERN Document Server

    Leinson, L B

    2012-01-01

    The complete spectrum of collective modes of the triplet order parameter in the superfluid neutron matter is examined in the BCS approximation below the pair-breaking threshold. The dispersion equations both for the unitary and nonunitary excitations are derived and solved in the limit of $q\\rightarrow0$ by taking into account the anisotropy of the energy gap for the case of $P$-wave pairing. By our analysis, there is only one Goldstone mode which is associated with the broken gauge symmetry. We found no additional Goldstone modes associated with the broken rotational symmetry but found that the oscillations of the total angular momentum are qualitatively similar to the "normal-flapping" mode in the A-phase of superfluid Helium. There are also two collective modes associated with internal vibrations of the structure of the order parameter oscillating with $\\omega(T=0) =1.20\\Delta_{0}$ and $\\omega(T=0) =0.61\\Delta_{0}$.

  14. Study of Kapton insulated superconducting coils manufactured for the LHC inner triplet model magnets at Fermilab

    CERN Document Server

    Andreev, N; Bossert, R; Brandt, J; Chichili, D R; Kerby, J S; Nobrega, A; Novitski, I; Ozelis, J P; Yadav, S; Zlobin, A V

    2000-01-01

    Fermilab has constructed a number of 2 m model quadrupoles as part of an ongoing program to develop and optimize the design of quadrupoles for the LHC Interaction Region inner triplets. The quadrupole design is based upon a two layer shell type coil of multi-filament NbTi strands in Rutherford cable, insulated with Kapton film. As such, the coil size and mechanical properties are critical in achieving the desired prestress and field quality targets for the agent. Throughout the model magnet program, different design and manufacturing techniques have been studied to obtain coils with the required mechanical properties. This paper summarizes the structural material and coil mechanical properties, coil design optimization results and production experience accumulated in the model R&D program. (5 refs).

  15. New 2D Thermal Model Applied to an LHC Inner Triplet Quadrupole Magnet

    CERN Document Server

    Bielert, ER; Ten Kate, HHJ; Verweij, AP

    2011-01-01

    A newly developed numerical model is presented that enables to compute two-dimensional heat transfer and temperature distributions over the cross-section of superconducting accelerator magnets. The entire thermal path from strand-in-cable to heat sink, including helium channels is considered. Superfluid helium properties are combined with temperature- and field-dependent non-linear solid material properties. Interfacial interactions are also taken into account. The model is applied to the cross-section of an inner triplet quadrupole magnet featuring a new concept for the ground insulation. Beam loss profiles are implemented as main heat source. It is concluded that operational margins can be considerably increased by opening additional thermal paths, improving the cooling conditions.

  16. Monozygotic Triplets and Dizygotic Twins following Transfer of Three Poor-Quality Cleavage Stage Embryos

    Directory of Open Access Journals (Sweden)

    Reshef Tal

    2012-01-01

    Full Text Available Background. Assisted reproductive technology has been linked to the increased incidence of monozygotic twinning. It is of clinical importance due to the increased risk of complications in multiple pregnancies in general and in monozygotic twins in particular. Case. A 29-year-old female, nulligravida underwent her first IVF cycle. Three poor-quality cleavage stage embryos were transferred resulting in monochorionic triamniotic triplets and dichorionic diamniotic twins. Selective embryo reduction was performed at 12 weeks leaving dichorionic twins. The patient underwent emergency cesarean section due to preterm labor and nonreassuring fetal heart tracing at 30 weeks of gestation. Conclusion. Our case emphasizes that even embryos with significant morphological abnormalities should be considered viable and the possibility of simultaneous spontaneous embryo splitting must be factored into determining number of embryos to transfer.

  17. Radiative corrections to the Higgs boson couplings in the Higgs triplet model

    CERN Document Server

    Kikuchi, Mariko

    2013-01-01

    We calculate Higgs coupling constants at one-loop level in the Higgs triplet model (HTM) to compare to future collider experiments. We evaluate the decay rate of the standard model (SM)-like Higgs boson ($h$) into diphoton. Renormalized Higgs couplings with the weak gauge bosons $hVV$ ($V=W$\\ and\\ $Z$) and the trilinear coupling $hhh$ are also calculated at the one-loop level in the on-shell scheme. The event rate of the $pp\\rightarrow h \\rightarrow \\gamma\\gamma$ channel in the HTM to the one in the SM can cover the value from the recent LHC data. We find that in the allowed parameter region by the current data, deviations in the one-loop corrected $hVV$ and $hhh$ vertices can be about -1% and +50%, respectively. Magnitudes of these deviations can be enough significant to compare with the precision future data at the International Linear Collider.

  18. High-fidelity singlet-triplet S -T- qubits in inhomogeneous magnetic fields

    Science.gov (United States)

    Wong, Clement H.; Eriksson, M. A.; Coppersmith, S. N.; Friesen, Mark

    2015-07-01

    We propose an optimized set of quantum gates for a singlet-triplet qubit in a double quantum dot with two electrons utilizing the S -T- subspace. Qubit rotations are driven by the applied magnetic field and a field gradient provided by a micromagnet. We optimize the fidelity of this qubit as a function of the magnetic fields, taking advantage of "sweet spots" where the rotation frequencies are independent of the energy level detuning, providing protection against charge noise. We simulate gate operations and qubit rotations in the presence of quasistatic noise from charge and nuclear spins as well as leakage to nonqubit states. Our results show that, for silicon quantum dots, gate fidelities greater than 99 % should be realizable, for rotations about two nearly orthogonal axes.

  19. Assessment and Mitigation of the Proton-Proton Collision Debris Impact on the FCC Triplet

    CERN Document Server

    Besana, Maria Ilaria; Fartoukh, Stephane; Martin, Roman; Tomás, Rogelio

    2016-01-01

    The Future Circular hadron Collider (FCC-hh), which is designed to operate at a centre-of-mass energy of 100 TeV and to deliver ambitious targets in terms of both instantaneous and integrated luminosity, poses extreme challenges in terms of machine protection during operation and with respect to long-term damages. Energy deposition studies are a crucial ingredient for its design. One of the relevant radiation sources are collision debris particles, which de- posit their energy in the interaction region elements and in particular in the superconducting magnet coils of the final focus triplet quadrupoles, to be protected from the risk of quenching and deterioration. In this contribution, the collision debris will be characterised and expectations obtained with FLUKA will be presented, including magnet lifetime considerations. New techniques including crossing angle gymnastics for peak dose deposition mitigation (as recently introduced in the framework of the LHC operation), will be discussed.

  20. Single Production of Doubly Charged Higgs Boson via e7 Collision in Higgs Triplet Model

    Institute of Scientific and Technical Information of China (English)

    苏雪松; 岳崇兴; 张娇; 王珏

    2011-01-01

    The Higgs triplet model (HTM) predicts the existence of a pair of doubly charged Higgs bosons H±±. Single production of H±± via e7 collision at the next generation e+ e- International Linear Collider (ILC) and the Large Hadron electron Collider (LHeC) is considered. The numerical results show that the production cross sections are very sensitive to the neutrino oscillation parameters. Their values for the inverted hierarchy mass spectrum are larger than those for the normal hierarchy mass spectrum at these two kinds of collider experiments. With reasonable values of the relevant free parameters, the possible signals of the doubly charged Higgs bosons predicted by the HTM might be detected in future ILC experiments.

  1. The Scalar Triplet Contribution to Lepton Flavour Violation and Neutrinoless Double Beta Decay in Left-Right Symmetric Model

    CERN Document Server

    Bambhaniya, Gulab; Goswami, Srubabati; Mitra, Manimala

    2015-01-01

    We analyse in detail the scalar triplet contribution to the low-energy lepton flavour violating (LFV) and lepton number violating (LNV) processes within a TeV-scale left-right symmetric framework. We show that in both type-I and type-II seesaw dominance for the light neutrino masses, the triplet of comparable or smaller mass than the largest right-handed neutrino mass scale can give sizeable contribution to the LFV processes, except in the quasi-degenerate limit of light neutrino masses, where a suppression can occur due to cancellations. In particular, a moderate value of the heaviest neutrino to scalar triplet mass ratio $r\\lesssim {\\cal O}(1)$ is still experimentally allowed and can be explored in the future LFV experiments. Similarly, the contribution of a relatively light triplet to the LNV process of neutrinoless double beta decay could be significant, disfavouring a part of the model parameter space otherwise allowed by LFV constraints. Nevertheless, we find regions of parameter space consistent with b...

  2. Two-Gap Superconductivity in LaNiGa_{2} with Nonunitary Triplet Pairing and Even Parity Gap Symmetry.

    Science.gov (United States)

    Weng, Z F; Zhang, J L; Smidman, M; Shang, T; Quintanilla, J; Annett, J F; Nicklas, M; Pang, G M; Jiao, L; Jiang, W B; Chen, Y; Steglich, F; Yuan, H Q

    2016-07-01

    The nature of the pairing states of superconducting LaNiC_{2} and LaNiGa_{2} has to date remained a puzzling question. Broken time reversal symmetry has been observed in both compounds and a group theoretical analysis implies a nonunitary triplet pairing state. However, all the allowed nonunitary triplet states have nodal gap functions but most thermodynamic and NMR measurements indicate fully gapped superconductivity in LaNiC_{2}. Here we probe the gap symmetry of LaNiGa_{2} by measuring the London penetration depth, specific heat, and upper critical field. These measurements demonstrate two-gap nodeless superconductivity in LaNiGa_{2}, suggesting that this is a common feature of both compounds. These results allow us to propose a novel triplet superconducting state, where the pairing occurs between electrons of the same spin, but on different orbitals. In this case the superconducting wave function has a triplet spin component but isotropic even parity gap symmetry, yet the overall wave function remains antisymmetric under particle exchange. This model leads to a nodeless two-gap superconducting state which breaks time reversal symmetry, and therefore accounts well for the seemingly contradictory experimental results. PMID:27447519

  3. UGC 3672: An unusual merging triplet of gas-rich galaxies in the Lynx-Cancer void

    CERN Document Server

    Chengalur, Jayaram N; Egorova, E S

    2016-01-01

    We present HI 21cm and optical observations of UGC 3672 which is located near the centre of the nearby Lynx-Cancer void. We find that UGC 3672 consists of an approximately linearly aligned triplet of gas rich dwarfs with large scale velocity continuity along the triplet axis. The faintest component of the triplet is extremely gas-rich (MHI/LB ~ 17) and also extremely metal deficient (12+log(O/H) ~ 7.0). The metallicity of this dwarf is close to the 'floor' observed in star forming galaxies. Low resolution HI images show that the galaxy triplet is located inside a common HI envelope, with fairly regular, disk like kinematics. At high angular resolution however, the gas is found to be confined to several filamentary tidal tails and bridges. The linear alignment of the galaxies, along with the velocity continuity that we observe, is consistent with the galaxies lying along a filament. We argue that the location of this highly unusual system in an extremely low density environment is not a coincidence, but is a c...

  4. Triplet repeat sequences in human DNA can be detected by hybridization to a synthetic (5'-CGG-3')17 oligodeoxyribonucleotide

    DEFF Research Database (Denmark)

    Behn-Krappa, A; Mollenhauer, J; Doerfler, W

    1993-01-01

    The seemingly autonomous amplification of naturally occurring triplet repeat sequences in the human genome has been implicated in the causation of human genetic disease, such as the fragile X (Martin-Bell) syndrome, myotonic dystrophy (Curshmann-Steinert), spinal and bulbar muscular atrophy...

  5. Singlet and Triplet Excitation Management in a Bichromophoric Near-Infrared-Phosphorescent BODIPY-Benzoporphyrin Platinum Complex

    KAUST Repository

    Whited, Matthew T.

    2011-01-12

    Multichromophoric arrays provide one strategy for assembling molecules with intense absorptions across the visible spectrum but are generally focused on systems that efficiently produce and manipulate singlet excitations and therefore are burdened by the restrictions of (a) unidirectional energy transfer and (b) limited tunability of the lowest molecular excited state. In contrast, we present here a multichromophoric array based on four boron dipyrrins (BODIPY) bound to a platinum benzoporphyrin scaffold that exhibits intense panchromatic absorption and efficiently generates triplets. The spectral complementarity of the BODIPY and porphryin units allows the direct observation of fast bidirectional singlet and triplet energy transfer processes (k ST(1BDP→1Por) = 7.8×1011 s-1, kTT(3Por→3BDP) = 1.0×1010 s-1, kTT(3BDP→ 3Por) = 1.6×1010 s-1), leading to a long-lived equilibrated [3BDP][Por]=[BDP][3Por] state. This equilibrated state contains approximately isoenergetic porphyrin and BODIPY triplets and exhibits efficient near-infrared phosphorescence (λem = 772 nm, φ = 0.26). Taken together, these studies show that appropriately designed triplet-utilizing arrays may overcome fundamental limitations typically associated with core-shell chromophores by tunable redistribution of energy from the core back onto the antennae. © 2010 American Chemical Society.

  6. Management of singlet and triplet excitons for efficient white organic light-emitting devices

    Science.gov (United States)

    Sun, Yiru; Giebink, Noel C.; Kanno, Hiroshi; Ma, Biwu; Thompson, Mark E.; Forrest, Stephen R.

    2006-04-01

    Lighting accounts for approximately 22 per cent of the electricity consumed in buildings in the United States, with 40 per cent of that amount consumed by inefficient (~15lmW-1) incandescent lamps. This has generated increased interest in the use of white electroluminescent organic light-emitting devices, owing to their potential for significantly improved efficiency over incandescent sources combined with low-cost, high-throughput manufacturability. The most impressive characteristics of such devices reported to date have been achieved in all-phosphor-doped devices, which have the potential for 100 per cent internal quantum efficiency: the phosphorescent molecules harness the triplet excitons that constitute three-quarters of the bound electron-hole pairs that form during charge injection, and which (unlike the remaining singlet excitons) would otherwise recombine non-radiatively. Here we introduce a different device concept that exploits a blue fluorescent molecule in exchange for a phosphorescent dopant, in combination with green and red phosphor dopants, to yield high power efficiency and stable colour balance, while maintaining the potential for unity internal quantum efficiency. Two distinct modes of energy transfer within this device serve to channel nearly all of the triplet energy to the phosphorescent dopants, retaining the singlet energy exclusively on the blue fluorescent dopant. Additionally, eliminating the exchange energy loss to the blue fluorophore allows for roughly 20 per cent increased power efficiency compared to a fully phosphorescent device. Our device challenges incandescent sources by exhibiting total external quantum and power efficiencies that peak at 18.7 +/- 0.5 per cent and 37.6 +/- 0.6lmW-1, respectively, decreasing to 18.4 +/- 0.5 per cent and 23.8 +/- 0.5lmW-1 at a high luminance of 500cdm-2.

  7. Tsallis q-triplet and Stock Market Indices: The cases of S & P 500 and TVIX

    Directory of Open Access Journals (Sweden)

    A. C. Iliopoulos

    2015-01-01

    Full Text Available In this study we present results of the evaluation of q − triplet of Tsallis non-extensive statistics concerning two time stock market time series, Standart & Poor’s 500 (S & P 500 and TVIX. The analysis of the results, support the hypothesis in which economic dynamics from physical point of view correspond to far from equilibrium spatial distributed non-linear dynamics. In particular, the analysis of the stock market time series revealed underlying complex dynamics, indicating clearly that the statistics of the dynamics in the multifractal phase space can be described by Tsallis distribution functions of power law and heavy tails forms. The non-extensive character of the underlying dynamics is related to the existence of long range interactions in space and time, as well as the interaction in many scales. In addition, the detailed analysis of S & P index unraveled the existence of non-equilibrium phase transitions depicted clearly in the variations of Tsallis q-triplet values. These phase transitions are connected with non-equilibrium stationary states of economical dynamics derived from processes of strong self organization which correspond to local maxima of Tsallis entropy, while the changes in the control parameters can induce new phase transitions and shifts to new metaequilibrium steady states of maximizing Tsallis entropy. These phase transitions lead to changes in Tsallis qtriplet values which correspond to multi-fractal changes in the formation of the phase state and an alteration in the phenomenology of the economical system. Finally, these characteristics also indicate the existence of fractional dynamics in the phase space which can be described through fractional Fokker-Planck equations and anomalous diffusion equations. The solutions of these equations are fractional spatiotemporal functions and non-Gaussian distributions functions which fall into the category of Levy distributions and Tsallis distributions.

  8. Spin-Free CC2 Implementation of Induced Transitions between Singlet Ground and Triplet Excited States.

    Science.gov (United States)

    Helmich-Paris, Benjamin; Hättig, Christof; van Wüllen, Christoph

    2016-04-12

    In most organic molecules, phosphorescence has its origin in transitions from triplet exited states to the singlet ground state, which are spin-forbidden in nonrelativistic quantum mechanics. A sufficiently accurate description of phosphorescence lifetimes for molecules that contain only light elements can be achieved by treating the spin-orbit coupling (SOC) with perturbation theory (PT). We present an efficient implementation of this approach for the approximate coupled cluster singles and doubles model CC2 in combination with the resolution-of-the-identity approximation for the electron repulsion integrals. The induced oscillator strengths and phosphorescence lifetimes from SOC-PT are computed within the response theory framework. In contrast to previous work, we employ an explicitly spin-coupled basis for singlet and triplet operators. Thereby, a spin-orbital treatment can be entirely avoided for closed-shell molecules. For compounds containing only light elements, the phosphorescence lifetimes obtained with SOC-PT-CC2 are in good agreement with those of exact two-component (X2C) CC2, whereas the calculations are roughly 12 times faster than with X2C. Phosphorescence lifetimes computed for two thioketones with the SOC-PT-CC2 approach agree very well with reference results from experiment and are similar to those obtained with multireference spin-orbit configuration interaction and with X2C-CC2. An application to phosphorescent emitters for metal-free organic light-emitting diodes (OLEDs) with almost 60 atoms and more than 1800 basis functions demonstrates how the approach extends the applicability of coupled cluster methods for studying phosphorescence. The results indicate that other decay channels like vibrational relaxation may become important in such systems if lifetimes are large.

  9. Improving Cartosat-1 DEM accuracy using synthetic stereo pair and triplet

    Science.gov (United States)

    Giribabu, D.; Srinivasa Rao, S.; Krishna Murthy, Y. V. N.

    2013-03-01

    Cartosat-1 is the first Indian Remote Sensing Satellite capable of providing along-track stereo images. Cartosat-1 provides forward stereo images with look angles +26° and -5° with respect to nadir for generating Digital Elevation Models (DEMs), Orthoimages and value added products for various applications. A pitch bias of -21° to the satellite resulted in giving reverse tilt mode stereo pair with look angles of +5° and -26° with respect to nadir. This paper compares DEMs generated using forward, reverse and other possible synthetic stereo pairs for two different types of topographies. Stereo triplet was used to generate DEM for Himalayan mountain topography to overcome the problem of occlusions. For flat to undulating topography it was shown that using Cartosat-1 synthetic stereo pair with look angles of -26° and +26° will produce improved version of DEM. Planimetric and height accuracy (Root Mean Square Error (RMSE)) of less than 2.5 m and 2.95 m respectively were obtained and qualitative analysis shows finer details in comparison with other DEMs. For rugged terrain and steep slopes of Himalayan mountain topography simple stereo pairs may not provide reliable accuracies in DEMs due to occlusions and shadows. Stereo triplet from Cartosat-1 was used to generate DEM for mountainous topography. This DEM shows better reconstruction of elevation model even at occluded region when compared with simple stereo pair based DEM. Planimetric and height accuracy (RMSE) of nearly 3 m were obtained and qualitative analysis shows reduction of outliers at occluded region.

  10. Electronic Absorption Spectroscopy and Franck-Condon Simulations for HC7H and MeC7H

    Science.gov (United States)

    Haenni, Benjamin C.; Shaffer, Christopher J.; Stanton, John F.; McMahon, Robert J.

    2014-06-01

    Highly unsaturated carbon chains of the HCnH family are important to the studies of combustion chemistry and the interstellar medium (ISM). Several members of this family (n=2,4,6) have been detected in the ISM by infrared spectroscopy. We have successfully matrix-isolated HC7H and MeC7H species and studied them using electronic absorption, FTIR, and EPR spectroscopy. The ground state potential energy surface was explored using ab initio (CCSD(T)/cc-pVTZ (fc)) methods to discover triplet minima for both species. Equation of motion coupled cluster calculations (EOM-CCSD/ANO1) of low-lying excited states allowed for Franck-Condon simulations. The comparison of the simulated spectra to the vibronic progression observed experimentally in the UV/Vis spectra permits assignment of a linear ground state triplet structure for both HC7H and MeC7H.

  11. A model for triplet mutation formation based on error-prone translesional DNA synthesis opposite UV photolesions.

    Science.gov (United States)

    Ikehata, Hironobu; Ono, Tetsuya; Tanaka, Kiyoji; Todo, Takeshi

    2007-05-01

    A triplet mutation is defined as multiple base substitutions or frameshifts within a three-nucleotide sequence which includes a dipyrimidine sequence. Triplet mutations have recently been identified as a new type of UV-specific mutation, although the mechanism of their formation is unknown. A total of 163 triplet mutations were identified through an extensive search of previously published data on UV-induced mutations, including mutations from skin, skin cancer, and cultured mammalian cells. Seven common patterns of sequence changes were found: Type I, NTC-->TTT; Type IIa, NCC-->PyTT or PyCT (Py, pyrimidine); Type IIb, TCC-->PuTT or PuCT (Pu, purine); Type III, NCC-->NAT or NTA; Type IV, NTT-->AAT; Type Va, NCT-->NTX; and Type Vb, PuCT-->XTT (N and X, independent anonymous bases). Furthermore, it is suggested that the type of UV lesion responsible for each of these triplet mutation classes are (a) pyrimidine(6-4)pyrimidone photoproducts for Types I, IIb, III, IV and Vb, (b) cyclobutane pyrimidine dimers for Type Va, and (c) Dewar valence isomers for Types IIa and IIb. These estimations are based primarily on results from previous studies using photolyases specific for each type of UV lesion. A model is proposed to explain the formation of each type of triplet mutation, based on error-prone translesional DNA synthesis opposite UV-specific photolesions. The model is largely consistent with the 'A-rule', and predicts error-prone insertions not only opposite photolesions but also opposite the undamaged template base one-nucleotide downstream from the lesions.

  12. Transient EPR Reveals Triplet State Delocalization in a Series of Cyclic and Linear π-Conjugated Porphyrin Oligomers.

    Science.gov (United States)

    Tait, Claudia E; Neuhaus, Patrik; Peeks, Martin D; Anderson, Harry L; Timmel, Christiane R

    2015-07-01

    The photoexcited triplet states of a series of linear and cyclic butadiyne-linked porphyrin oligomers were investigated by transient Electron Paramagnetic Resonance (EPR) and Electron Nuclear DOuble Resonance (ENDOR). The spatial delocalization of the triplet state wave function in systems with different numbers of porphyrin units and different geometries was analyzed in terms of zero-field splitting parameters and proton hyperfine couplings. Even though no significant change in the zero-field splitting parameters (D and E) is observed for linear oligomers with two to six porphyrin units, the spin polarization of the transient EPR spectra is particularly sensitive to the number of porphyrin units, implying a change of the mechanism of intersystem crossing. Analysis of the proton hyperfine couplings in linear oligomers with more than two porphyrin units, in combination with density functional theory calculations, indicates that the spin density is localized mainly on two to three porphyrin units rather than being distributed evenly over the whole π-system. The sensitivity of the zero-field splitting parameters to changes in geometry was investigated by comparing free linear oligomers with oligomers bound to a hexapyridyl template. Significant changes in the zero-field splitting parameter D were observed, while the proton hyperfine couplings show no change in the extent of triplet state delocalization. The triplet state of the cyclic porphyrin hexamer has a much decreased zero-field splitting parameter D and much smaller proton hyperfine couplings with respect to the monomeric unit, indicating complete delocalization over six porphyrin units in this symmetric system. This surprising result provides the first evidence for extensive triplet state delocalization in an artificial supramolecular assembly of porphyrins. PMID:26035477

  13. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    2008-01-01

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

  14. Spin-free intermediate Hamiltonian Fock space coupled-cluster theory with full inclusion of triple excitations for restricted Hartree Fock based triplet states.

    Science.gov (United States)

    Musial, Monika; Bartlett, Rodney J

    2008-12-28

    The recently reported inclusion of the connected triples into the intermediate Hamiltonian realization of the Fock space coupled-cluster (IH-FS-CC) theory [M. Musial and R. J. Bartlett, J. Chem. Phys. 129, 044101 (2008)] is extended to produce the triplet states. This is done entirely in spatial orbitals on the basis of the double occupancy in the restricted Hartree Fock reference function. New equations for the triplet state amplitudes expressed in terms of the Goldstone diagrams are derived and implemented. Several applications show the usefulness of the IH-FS-CC scheme to describe the triplet states with the computational gains inherent to a spin-free implementation.

  15. Simultaneous improvement of emission color, singlet-triplet energy gap, and quantum efficiency of blue thermally activated delayed fluorescent emitters using a 1-carbazolylcarbazole based donor.

    Science.gov (United States)

    Kim, Mounggon; Choi, Jeong Min; Lee, Jun Yeob

    2016-08-21

    Blue thermally activated delayed fluorescent (TADF) emitters having 1-carbazolylcarbazole based donor moieties were developed to resolve the low quantum efficiency and large singlet-triplet energy splitting issues of the linker free TADF emitters. Investigation of the 1-carbazolylcarbazole derived donors as the donor units of two blue TADF emitters in comparison with 3-carbazolylcarbazole demonstrated that the 1-carbazolylcarbazole based donors increased the triplet energy, decreased the singlet-triplet energy gap, blue-shifted the emission color, and enhanced the quantum efficiency of the blue TADF devices. PMID:27443818

  16. Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    The emission and absorption of photons taking place without changes in the frequency spectrum of the crystal lattice are known as the Moessbauer effect. It takes place in the low energy levels of heavy nuclei in solid lattices at low temperatures. On the basis of the hyperfine structure of Moessbauer spectra the notions are explained of isomer shift, quadrupole splitting and magnetic splitting. The principle and function are explained of Moessbauer spectrometers and the methods of graphical processing of spectra, also the use of the least square fit. Moessbauer spectroscopy is nondestructive, highly sensitive and selective and makes structural resolution possible. It is used for quantitative and qualitative analysis of compounds. Examples are given of the use of this method for mineralogical and crystallo-chemical analysis of lunar minerals and rocks, for analysis of corrosion products of iron and for phase analysis of alloys. (M.D.)

  17. Strongly frustrated triangular spin lattice emerging from triplet dimer formation in honeycomb Li2IrO3

    Science.gov (United States)

    Nishimoto, Satoshi; Katukuri, Vamshi M.; Yushankhai, Viktor; Stoll, Hermann; Rößler, Ulrich K.; Hozoi, Liviu; Rousochatzakis, Ioannis; van den Brink, Jeroen

    2016-01-01

    Iridium oxides with a honeycomb lattice have been identified as platforms for the much anticipated Kitaev topological spin liquid: the spin-orbit entangled states of Ir4+ in principle generate precisely the required type of anisotropic exchange. However, other magnetic couplings can drive the system away from the spin-liquid phase. With this in mind, here we disentangle the different magnetic interactions in Li2IrO3, a honeycomb iridate with two crystallographically inequivalent sets of adjacent Ir sites. Our ab initio many-body calculations show that, while both Heisenberg and Kitaev nearest-neighbour couplings are present, on one set of Ir-Ir bonds the former dominates, resulting in the formation of spin-triplet dimers. The triplet dimers frame a strongly frustrated triangular lattice and by exact cluster diagonalization we show that they remain protected in a wide region of the phase diagram.

  18. Strongly frustrated triangular spin lattice emerging from triplet dimer formation in honeycomb Li2IrO3

    Science.gov (United States)

    Nishimoto, Satoshi; Katukuri, Vamshi M.; Yushankhai, Viktor; Stoll, Hermann; Rößler, Ulrich K.; Hozoi, Liviu; Rousochatzakis, Ioannis; van den Brink, Jeroen

    2016-01-01

    Iridium oxides with a honeycomb lattice have been identified as platforms for the much anticipated Kitaev topological spin liquid: the spin-orbit entangled states of Ir4+ in principle generate precisely the required type of anisotropic exchange. However, other magnetic couplings can drive the system away from the spin-liquid phase. With this in mind, here we disentangle the different magnetic interactions in Li2IrO3, a honeycomb iridate with two crystallographically inequivalent sets of adjacent Ir sites. Our ab initio many-body calculations show that, while both Heisenberg and Kitaev nearest-neighbour couplings are present, on one set of Ir–Ir bonds the former dominates, resulting in the formation of spin-triplet dimers. The triplet dimers frame a strongly frustrated triangular lattice and by exact cluster diagonalization we show that they remain protected in a wide region of the phase diagram. PMID:26776664

  19. Effect of Triplet Harvesting on the Lifetime Based on Fluorescence and Phosphorescence in Hybrid White Organic Light Emitting Diodes.

    Science.gov (United States)

    Lee, Eun; Lee, Ho Won; Yang, Hyung Jin; Sun, Yong; Lee, Jae Woo; Hwang, Kyo Min; Kim, Woo Young; Kim, Young Kwan

    2016-03-01

    We investigated efficient hybrid white organic light emitting diodes (WOLEDs) apply to triplet harvesting (TH) concept based on three complementary colors by mixing containing blue fluorescent emitter with phosphorescent emitters. The TH is to transfer these triplet excitons from a fluorescence to a phosphorescence, where they can decay radiatively. We fabricated several hybrid WOLEDs, having various emitting layer structures with blue fluorescent emitter and red, green phosphorescent emitter. The WOLED exhibited maximum luminous efficiency of 9.02 cd/A, and a maximum external quantum efficiency of 4.17%. The WOLED showed a highly color-stable white emission with the Commission International de L'Éclairage chromaticity of (0.38, 0.36) at 1,000 cd/m2. PMID:27455693

  20. DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen)

    CERN Document Server

    Wouters, Sebastian; Van Der Voort, Pascal; Van Speybroeck, Veronique; Van Neck, Dimitri

    2014-01-01

    We use CheMPS2, our free open-source spin-adapted implementation of the density matrix renormalization group (DMRG) [Wouters et al., Comput. Phys. Commun. 185, 1501 (2014)], to study the lowest singlet, triplet, and quintet states of the oxo-Mn(Salen) complex. We describe how an initial approximate DMRG calculation in a large active space around the Fermi level can be used to obtain a good set of starting orbitals for subsequent complete-active-space or DMRG self-consistent field (CASSCF or DMRG-SCF) calculations. This procedure mitigates the need for a localization procedure, followed by a manual selection of the active space. Per multiplicity, the same active space of 28 electrons in 22 orbitals (28e, 22o) is obtained with the 6-31G*, cc-pVDZ, and ANO-RCC-VDZP basis sets (the latter with DKH2 scalar relativistic corrections). Our calculations provide new insight into the electronic structure of the quintet.

  1. Experimental triplet and quadruplet fluctuation densities and spatial distribution function integrals for pure liquids.

    Science.gov (United States)

    Ploetz, Elizabeth A; Karunaweera, Sadish; Smith, Paul E

    2015-01-28

    Fluctuation solution theory has provided an alternative view of many liquid mixture properties in terms of particle number fluctuations. The particle number fluctuations can also be related to integrals of the corresponding two body distribution functions between molecular pairs in order to provide a more physical picture of solution behavior and molecule affinities. Here, we extend this type of approach to provide expressions for higher order triplet and quadruplet fluctuations, and thereby integrals over the corresponding distribution functions, all of which can be obtained from available experimental thermodynamic data. The fluctuations and integrals are then determined using the International Association for the Properties of Water and Steam Formulation 1995 (IAPWS-95) equation of state for the liquid phase of pure water. The results indicate small, but significant, deviations from a Gaussian distribution for the molecules in this system. The pressure and temperature dependence of the fluctuations and integrals, as well as the limiting behavior as one approaches both the triple point and the critical point, are also examined. PMID:25637990

  2. Walking Down the Chalcogenic Group of the Periodic Table: From Singlet to Triplet Organic Emitters.

    Science.gov (United States)

    Kremer, Adrian; Aurisicchio, Claudia; De Leo, Federica; Ventura, Barbara; Wouters, Johan; Armaroli, Nicola; Barbieri, Andrea; Bonifazi, Davide

    2015-10-19

    The synthesis, X-ray crystal structures, ground- and excited-state UV/Vis absorption spectra, and luminescence properties of chalcogen-doped organic emitters equipped on both extremities with benzoxa-, benzothia-, benzoselena- and benzotellurazole (1X and 2X ) moieties have been reported for the first time. The insertion of the four different chalcogen atoms within the same molecular skeleton enables the investigation of only the chalcogenic effect on the organisation and photophysical properties of the material. Detailed crystal-structure analyses provide evidence of similar packing for 2O -2Se , in which the benzoazoles are engaged in π-π stacking and, for the heavier atoms, in secondary X⋅⋅⋅X and X⋅⋅⋅N bonding interactions. Detailed computational analysis shows that the arrangement is essentially governed by the interplay of van der Waals and secondary bonding interactions. Progressive quenching of the fluorescence and concomitant onset of phosphorescence features with gradually shorter lifetimes are detected as the atomic weight of the chalcogen heteroatom increases, with the tellurium-doped derivatives exhibiting only emission from the lowest triplet excited state. Notably, the phosphorescence spectra of the selenium and tellurium derivatives can be recorded even at room temperature; this is a very rare finding for fully organic emitters. PMID:26471446

  3. Field quality of the LHC inner triplet quadrupoles being fabricated at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Gueorgui V. Velev et al.

    2003-06-02

    Fermilab, as part of the US-LHC Accelerator Project, has designed and is producing superconducting low-beta quadrupole magnets for the Large Hadron Collider (LHC). These 70 mm bore, 5.5 m long magnets operate in superfluid helium at 1.9 K with a maximum operating gradient of 214 T/m. Two quadrupoles, combined with a dipole orbit corrector, form a single LQXB cryogenic assembly, the Q2 optical element of the final focus triplets in the LHC interaction regions. Field quality was measured at room temperature during fabrication of the cold masses as well as at superfluid helium temperature in two thermal cycles for the first LQXB cryogenic assembly. Integral cold measurements were made with a 7.1 m long rotating coil and with a 0.8 m long rotating coil at 8 axial positions and in a range of currents. In addition to the magnetic measurements, this paper reports on the quench performance of the cold masses and on the measurements of their internal alignment.

  4. Search for double charmonium decays of the P-wave spin-triplet bottomonium states

    CERN Document Server

    Shen, C P; Iijima, T

    2012-01-01

    Using a sample of 158 million $\\Upsilon(2S)$ events collected with the Belle detector, we search for the first time for double charmonium decays of the $P$-wave spin-triplet bottomonium states ($\\Upsilon(2S) \\to \\gamma \\chi_{bJ}$, $\\chi_{bJ} \\to \\jpsi \\jpsi$, $\\jpsi \\psp$, $\\psp \\psp$ for J=0, 1, and 2). No significant $\\chi_{bJ}$ signal is observed in the double charmonium mass spectra, and we obtain the following upper limits, $\\BR(\\chi_{bJ} \\to \\jpsi \\jpsi)<7.1\\times 10^{-5}$, $2.7\\times 10^{-5}$, $4.5\\times 10^{-5}$, $\\BR(\\chi_{bJ} \\to \\jpsi \\psp)<1.2\\times 10^{-4}$, $1.7\\times 10^{-5}$, $4.9\\times 10^{-5}$, $\\BR(\\chi_{bJ} \\to \\psp \\psp)<3.1\\times 10^{-5}$, $6.2\\times 10^{-5}$, $1.6\\times 10^{-5}$ for J=0, 1, and 2, respectively, at the 90% confidence level. These limits are significantly lower than the central values (with uncertainties of 50% to 70%) predicted using the light cone formalism but are consistent with calculations using the NRQCD factorization approach.

  5. The Displaced Dusty ISM of NGC 3077: Tidal Stripping in the M 81 Triplet

    CERN Document Server

    Walter, Fabian; Aniano, G; Calzetti, D; Croxall, K; Dale, D A; Draine, B T; Engelbracht, C; Hinz, J; Kennicutt, R C; Wolfire, M; Armus, L; Beirao, P; Bolatto, A D; Brandl, B; Crocker, A; Galametz, M; Groves, B; Hao, C -N; Helou, G; Hunt, L; Koda, J; Krause, O; Leroy, A; Meidt, S; Murphy, E J; Rahman, N; Rix, H -W; Roussel, H; Sauvage, M; Schinnerer, E; Skibba, R; Smith, J D; Wilson, C D; Zibetti, S

    2011-01-01

    We present the detection of extended (~30 kpc^2) dust emission in the tidal \\hi\\ arm near NGC 3077 (member of the M\\,81 triplet) using SPIRE on board Herschel. Dust emission in the tidal arm is typically detected where the \\hi\\ column densities are >10^21 cm^-2. The SPIRE band ratios show that the dust in the tidal arm is significantly colder (~13 K) than in NGC 3077 itself (~31 K), consistent with the lower radiation field in the tidal arm. The total dust mass in the tidal arm is ~1.8 x 10^6 M_sun (assuming beta=2), i.e. substantially larger than the dust mass associated with NGC 3077 (~2 x 10^5 M_sun). Where dust is detected, the dust-to-gas ratio is 6+/-3 x 10^-3, consistent within the uncertainties with what is found in NGC 3077 and nearby spiral galaxies with Galactic metallicities. The faint HII regions in the tidal arm can not be responsible for the detected enriched material and are not the main source of the dust heating in the tidal arm. We conclude that the interstellar medium (atomic HI, molecules...

  6. Spin-triplet electron transport in hybrid superconductor heterostructures with a composite ferromagnetic interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Sheyerman, A. E., E-mail: karen@hitech.cplire.ru; Constantinian, K. Y.; Ovsyannikov, G. A.; Kislinskii, Yu. V.; Shadrin, A. V. [Russian Academy of Sciences, Kotelnikov Institute of Radio Engineering and Electronics (Russian Federation); Kalabukhov, A. V. [Chalmers University of Technology (Sweden); Khaydukov, Yu. N. [Max-Planck Institute for Solid State Research (Germany)

    2015-06-15

    Hybrid YBa{sub 2}Cu{sub 3}O{sub 7−x}/SrRuO{sub 3}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/Au-Nb superconductor mesastructures with a composite manganite-ruthenate ferromagnetic interlayer are studied using electrophysical, magnetic, and microwave methods. The supercurrent in the mesastructure is observed when the interlayer thickness is much larger than the coherence length of ferromagnetic materials. The peak on the dependence of the critical current density on the interlayer material thickness corresponds to the coherence length, which is in qualitative agreement with theoretical predictions for a system with spit-triplet superconducting correlations. The magnetic-field dependence of the critical current is determined by penetration of magnetic flux quanta and by the magnetic domain structure, as well as by the field dependence of disorientation of the magnetization vectors of the layers in the composite magnetic interlayer. It is found that the supercurrent exists in magnetic fields two orders of magnitude stronger than the field corresponding to entry of a magnetic flux quantum into the mesastructure. The current-phase relation (CPR) of the supercurrent of mesastructures is investigated upon a change in the magnetic field from zero to 30 Oe; the ratio of the second CPR harmonic to the first, determined from the dependence of the Shapiro steps on the microwave radiation amplitude, does not exceed 50%.

  7. Optimization of Triplet Quadrupoles Field Quality for the LHC High Luminosity Lattice at Collision Energy

    CERN Document Server

    Nosochkov, Y; Wang, MH; Fartoukh, S; Giovannozzi, M; de Maria, R; McIntosh, E

    2013-01-01

    Beta functions at two interaction points (IP) in the high luminosity LHC upgrade lattice (HL-LHC) at collision energy will be significantly reduced compared to the nominal LHC lattice. This will result in much higher beta functions in the inner triplet (IT) quadrupoles adjacent to these IPs. The consequences are a larger beam size in these quadrupoles, higher IT chromaticity, and stronger effects of the IT field errors on dynamic aperture (DA). The IT chromaticity will be compensated using the Achromatic Telescopic Squeezing scheme [1]. The increased IT beam size will be accommodated by installing large aperture Nb3Sn superconducting quadrupoles with 150 mm coil diameter. The stronger effects of the IT field errors can be remedied by optimizing the IT field error specifications. The latter must satisfy two conditions: provide an acceptable DA and be compatible with realistically achievable field quality. Optimization of the IT field errors was performed for the LHC upgrade layout version SLHCV3.01 with IT gra...

  8. The Nature of the Singlet and Triplet States of Cyclobutadiene as Revealed by Quantum Interference.

    Science.gov (United States)

    Fantuzzi, Felipe; Cardozo, Thiago M; Nascimento, Marco A C

    2016-01-18

    The generalized product function energy partitioning (GPF-EP) method is applied to the description of the cyclobutadiene molecule. The GPF wave function was built to reproduce generalized valence bond (GVB) and spin-coupled (SC) wave functions. The influence of quasiclassical and quantum interference contributions to each chemical bond of the system are analyzed along the automerization reaction coordinate for the lowest singlet and triplet states. The results show that the interference effect on the π space reduces the electronic energy of the singlet cyclobutadiene relative to the second-order Jahn-Teller distortion, which takes the molecule from a D4h to a D2h structure. Our results also suggest that the π space of the (1) B1g state of the square cyclobutadiene is composed of a weak four center-four electron bond, whereas the (3) A2g state has a four center-two electron π bond. Finally, we also show that, although strain effects are nonnegligible, the thermodynamics of the main decomposition pathway of cyclobutadiene in the gas phase is dominated by the π space interference.

  9. Photoexcited triplet state provides a quantitative measure of intercalating drug-DNA binding energies

    Science.gov (United States)

    Maki, August H.; Alfredson, T. V.; Waring, M. J.

    1992-04-01

    A linear correlation between spectroscopic and thermodynamic properties of systems is rarely encountered. In triplet state ODMR studies of various DNA complexes of echinomycin, a quinoxaline-containing cyclic depsipeptide bis-intercalating antibiotic, and its biosynthesized quinoline analogs, such correlations are observed. The zero field splitting D-parameter of the intercalated quinoxaline or quinoline residue varies linearly with the free energy of drug-DNA complexing. From previous work, the DNA sequence specificity of echinomycin analogs is known to be influenced by the identity of the intercalating residue (e.g., quinoxaline vs. quinoline). The present results strongly suggest that the DNA sequence-specificity of these drugs is controlled largely by the intercalated residue, and that the energetics of the peptide- DNA interaction, although considerable, are relatively sequence independent. These conclusions run counter to the generally accepted idea that DNA recognition by sequence- seeking proteins is controlled by specific hydrogen bonding interactions. The high degree of N-methylation of the echinomycin peptide portion severely restricts these interactions, however. A simple theoretical model is presented to support the experimentally observed linear correlation between (Delta) D and (Delta) G.

  10. On intrinsic structure of wave function of fermion triplet in external monopole field

    CERN Document Server

    Redkov, V M

    1999-01-01

    Using the Weyl-Tetrode-Fock spinor formalism, the fermion triplet in the 't Hooft-Polyakov monopole field is examined all over again. Spherical solutions corresponding to the total conserved momentum J =l + S + T are constructed. The angular dependence is expressed in terms of the Wigner's functions. The radial system of 12 equations decomposes into two sub-systems by diagonalizing some complicated inversion operator. The case of minimal j = 1/2 is considered separately. A more detailed analysis is accomplished for the case of simplest monopole field: namely, the one produced by putting the Dirac potential into the non-Abelian scheme. Now a discrete operation diagonalized contains an additional complex parameter A. The same parameter enters wave functions. This quantity can manifest itself at matrix elements. In particular, there have been analyzed the N(A)-parity selection rules: those depending on the A. As shown, the A-freedom is a consequence of the existence of additional symmetry of the relevant Hamilto...

  11. Combustion stability characteristics of the model chamber with various configurations of triplet impinging-jet injectors

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Chae Hoon [Chosun University, Gwangju (Korea, Republic of); Seol, Woo Seok [Korea Aerospace Research Institute, Daejeon (Korea, Republic of); Shibanov, Alexander A. [Research Institute of Chemical Machine Building, Sergiev Posad (Russian Federation)

    2006-06-15

    Combustion stability characteristics in actual full-scale combustion chamber of a rocket engine are investigated by experimental tests with the model (sub-scale) chamber. The present hot-fire tests adopt the combustion chamber with three configurations of triplet impinging-jet injectors such as F-O-O-F, F-O-F, and O-F-O configurations. Combustion stability boundaries are obtained and presented by the parameters of combustion-chamber pressure and mixture (oxidizer/fuel) ratio. From the experimental tests, two instability regions are observed and the pressure oscillations have the similar patterns irrespective of injector configuration. But, the O-F-O injector configuration shows broader upper-instability region than the other configurations. To verify the instability mechanism for the lower and upper instability regions, air-purge acoustic test is conducted and the photograph of the flames is taken. As a result, it is found that the pressure oscillations in the two regions can be characterized by the first impinging point of hydraulic jets and pre-blowout combustion, respectively.

  12. Potential energy surface of triplet N{sub 2}O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Zoltan; Meana-Pañeda, Rubén; Song, Guoliang; Paukku, Yuliya; Truhlar, Donald G., E-mail: truhlar@umn.edu [Department of Chemistry, Chemical Theory Center, and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431 (United States)

    2016-01-14

    We present a global ground-state triplet potential energy surface for the N{sub 2}O{sub 2} system that is suitable for treating high-energy vibrational-rotational energy transfer and collision-induced dissociation. The surface is based on multi-state complete-active-space second-order perturbation theory/minimally augmented correlation-consistent polarized valence triple-zeta electronic structure calculations plus dynamically scaled external correlation. In the multireference calculations, the active space has 14 electrons in 12 orbitals. The calculations cover nine arrangements corresponding to dissociative diatom-diatom collisions of N{sub 2}, O{sub 2}, and nitric oxide (NO), the interaction of a triatomic molecule (N{sub 2}O and NO{sub 2}) with the fourth atom, and the interaction of a diatomic molecule with a single atom (i.e., the triatomic subsystems). The global ground-state potential energy surface was obtained by fitting the many-body interaction to 54 889 electronic structure data points with a fitting function that is a permutationally invariant polynomial in terms of bond-order functions of the six interatomic distances.

  13. Non-LTE inversions of the Mg II h&k and UV triplet lines

    CERN Document Server

    Rodríguez, Jaime de la Cruz; Ramos, Andrés Asensio

    2016-01-01

    The Mg II h&k lines are powerful diagnostics for studying the solar chromosphere. They have become particularly popular with the launch of the IRIS satellite, and a number of studies that include these lines have lead to great progress in understanding chromospheric heating, in many cases thanks to the support from 3D MHD simulations. In this study we utilize another approach to analyze observations: non-LTE inversions of the Mg II h&k and UV triplet lines including the effects of partial redistribution. Our inversion code attempts to construct a model atmosphere that is compatible with the observed spectra. We have assessed the capabilities and limitations of the inversions using the FALC atmosphere and a snapshot from a 3D radiation-MHD simulation. We find that Mg II h&k allow reconstructing a model atmosphere from the middle photosphere to the transition region. We have also explored the capabilities of a multi-line/multi-atom setup, including the Mg II h&k, the Ca II 854.2 nm and the Fe I ...

  14. Application of the short and long consecutive pairs model to the triplet-doublet interaction in molecular crystals

    Science.gov (United States)

    Barhoumi, T.; Monge, J. L.; Bouchriha, H.

    2010-10-01

    We have adapted the model of two consecutive pairs to the study of the triplet-doublet (T-D) interaction in molecular crystals. We have applied this model to the modulation of the photoconductivity in crystalline anthracene by a static magnetic field (MFE) and a microwave field (PDMR). We were able to reproduce, for the first time, quite perfectly two types of experiments with the same set of kinetic constants.

  15. Energy Landscapes of Dynamic Ensembles of Rolling Triplet Repeat Bulge Loops: Implications for DNA Expansion Associated with Disease States

    OpenAIRE

    Völker, Jens; Gindikin, Vera; Klump, Horst H.; Plum, G. Eric; Breslauer, Kenneth J.

    2012-01-01

    DNA repeat domains can form ensembles of canonical and noncanonical states, including stable and metastable DNA secondary structures. Such sequence-induced structural diversity creates complex conformational landscapes for DNA processing pathways, including those triplet expansion events that accompany replication, recombination, and/or repair. Here we demonstrate further levels of conformational complexity within repeat domains. Specifically, we show that bulge loop structures within an exte...

  16. Protecting the primordial baryon asymmetry in the $SU(2)_{L}$ triplet Higgs model compatible with KamLAND and WMAP

    OpenAIRE

    Hasegawa, K

    2004-01-01

    We find the condition that the primordial baryon asymmetry is not washed out in the $SU(2)_{L}$ triplet Higgs model by solving the Boltzmann equation. We further require that the model is compatible with the recent results of the neutrino oscillation experiments and WMAP, and the constraints on the $\\rho$ parameter imposed by the LEP. We finally obtain the allowed region of the parameters in the model.

  17. Synthesis of skeletally diverse alkaloid-like molecules: exploitation of metathesis substrates assembled from triplets of building blocks

    OpenAIRE

    Maurya, Sushil K.; Mark Dow; Stuart Warriner; Adam Nelson

    2013-01-01

    A range of metathesis substrates was assembled from triplets of unsaturated building blocks. The approach involved the iterative attachment of a propagating and a terminating building block to a fluorous-tagged initiating building block. Metathesis cascade chemistry was used to “reprogram” the molecular scaffolds. Remarkably, in one case, a cyclopropanation reaction competed with the expected metathesis cascade process. Finally, it was demonstrated that the metathesis products could be deriva...

  18. Interband coulomb interaction and horizontal line nodes in triplet superconductor Sr sub 2 RuO sub 4

    CERN Document Server

    Hasegawa, Y

    2003-01-01

    A possible mechanism for appearance of the horizontal line nodes in triplet superconductor, Sr sub 2 RuO sub 4 , is proposed. We consider the interlayer Coulomb interaction, as well as the on-site Coulomb repulsion, between electrons in different bands. In the second order perturbation of the interband interaction, the effective interaction becomes dependent on cos q sub z /2, resulting in horizontal line nodes. (author)

  19. Unraveling Triplet Excitons Photophysics in Hyper-Cross-Linked Polymeric Nanoparticles: Toward the Next Generation of Solid-State Upconverting Materials.

    Science.gov (United States)

    Monguzzi, Angelo; Mauri, Michele; Frigoli, Michel; Pedrini, Jacopo; Simonutti, Roberto; Larpent, Chantal; Vaccaro, Gianfranco; Sassi, Mauro; Meinardi, Francesco

    2016-07-21

    The technological application of sensitized upconversion based on triplet-triplet annihilation (TTA) requires the transition from systems operating in liquid solutions to solid-state materials. Here, we demonstrate that the high upconversion efficiency reported in hyper-cross-linked nanoparticles does not originate from residual mobility of the embedded dyes as it happens in soft hosts. The hyper-reticulation from one side blocks the dyes in fixed positions, but on the other one, it suppresses the nonradiative spontaneous decay of the triplet excitons, reducing intramolecular relaxations. TTA is thus enabled by an unprecedented extension of the triplet lifetime, which grants long excitons diffusion lengths by hopping among the dye framework and gives rise to high upconversion yield without any molecular displacement. This finding paves the way for the design of a new class of upconverting materials, which in principle can operate at excitation intensities even lower than those requested in liquid or in rubber hosts. PMID:27388582

  20. Sulphur abundances in halo giants from the [S ı] line at 1082 nm and the [S ı] triplet around 1045 nm

    DEFF Research Database (Denmark)

    Jönsson, H.; Ryde, N.; Nissen, Poul Erik;

    2011-01-01

    to clarify this situation by measuring the sulphur abundance in a sample of halo giants using two diagnostics: the S i triplet around 1045 nm and the [S i] line at 1082 nm. The latter of the two is not believed to be sensitive to non-LTE effects. We can thereby minimize the uncertainties in the diagnostic...... used and estimate the usefulness of the triplet for the sulphur determination in halo K giants. We will also be able to compare our sulphur abundance differences from the two diagnostics with the expected non-LTE effects in the 1045 nm triplet previously calculated by others. Methods. High...... diagnostics using tailored 1D model atmospheres and relying on non-LTE corrections from the litterature. Effects of convective inhomogeneities in the stellar atmospheres are investigated. Results. The sulphur abundances derived from both the [S i] line and the non-LTE corrected 1045 nm triplet favor a flat...

  1. A Conserved Proline Triplet in Val-tRNA Synthetase and the Origin of Elongation Factor P

    Directory of Open Access Journals (Sweden)

    Agata L. Starosta

    2014-10-01

    Full Text Available Bacterial ribosomes stall on polyproline stretches and require the elongation factor P (EF-P to relieve the arrest. Yet it remains unclear why evolution has favored the development of EF-P rather than selecting against the occurrence of polyproline stretches in proteins. We have discovered that only a single polyproline stretch is invariant across all domains of life, namely a proline triplet in ValS, the tRNA synthetase, that charges tRNAVal with valine. Here, we show that expression of ValS in vivo and in vitro requires EF-P and demonstrate that the proline triplet located in the active site of ValS is important for efficient charging of tRNAVal with valine and preventing formation of mischarged Thr-tRNAVal as well as efficient growth of E. coli in vivo. We suggest that the critical role of the proline triplet for ValS activity may explain why bacterial cells coevolved the EF-P rescue system.

  2. Triplet harvesting with 100% efficiency by way of thermally activated delayed fluorescence in charge transfer OLED emitters.

    Science.gov (United States)

    Dias, Fernando B; Bourdakos, Konstantinos N; Jankus, Vygintas; Moss, Kathryn C; Kamtekar, Kiran T; Bhalla, Vandana; Santos, José; Bryce, Martin R; Monkman, Andrew P

    2013-07-19

    Organic light-emitting diodes (OLEDs) have their performance limited by the number of emissive singlet states created upon charge recombination (25%). Recently, a novel strategy has been proposed, based on thermally activated up-conversion of triplet to singlet states, yielding delayed fluorescence (TADF), which greatly enhances electroluminescence. The energy barrier for this reverse intersystem crossing mechanism is proportional to the exchange energy (ΔEST ) between the singlet and triplet states; therefore, materials with intramolecular charge transfer (ICT) states, where it is known that the exchange energy is small, are perfect candidates. However, here it is shown that triplet states can be harvested with 100% efficiency via TADF, even in materials with ΔEST of more than 20 kT (where k is the Boltzmann constant and T is the temperature) at room temperature. The key role played by lone pair electrons in achieving this high efficiency in a series of ICT molecules is elucidated. The results show the complex photophysics of efficient TADF materials and give clear guidelines for designing new emitters. PMID:23703877

  3. A fluorescence detected magnetic resonance investigation of the carotenoid triplet states associated with Photosystem II of isolated spinach thylakoid membranes

    CERN Document Server

    Santabarbara, S; Carbonera, D; Heathcote, P

    2005-01-01

    The carotenoid triplet populations associated with the fluorescence emission chlorophyll forms of Photosystem II have been investigated in isolated spinach thylakoid membranes by means of fluorescence detected magnetic resonance in zero field (FDMR). The spectra collected in the 680-690 nm emission range, have been fitted by a global analysis procedure. At least five different carotenoid triplet states coupled to the terminal emitting chlorophyll forms of PS II, peaking at 682 nm, 687 nm and 692 nm, have been characterised. The triplets associated with the outer antenna emission forms, at 682 nm, have zero field splitting parameters D = 0.0385 cm/sup -1/, E = 0.00367 cm/sup -1/; D = 0.0404 cm/sup -1/, E = 0.00379 cm/sup -1/ and D = 0.0386 cm/sup -1/, E = 0.00406 cm/sup -1/ which are very similar to those previously reported for the xanthophylls of the isolated LHC II complex. Therefore the FDMR spectra recorded in this work provide insights into the organisation of the LHC II complex in the unperturbed enviro...

  4. Preliminary Data Analysis on the 2011-2012 Heat Load of the LHC Inner Triplets and Stand Alone Magnets

    CERN Document Server

    Hulsman, Johannes

    2014-01-01

    Electron clouds generated inside the LHC beam chamber deposit heat to the beam walls. These heat signatures provide valuable information to understand the behavior of electron clouds under certain circumstances. The heat loads from the Inner Triplets and the Stand Alone Magnets (SAMs) are used for this investigation. The data of the inner triplets confirmed with previous studies about the fact that two 50ns beams are required for a significant electron cloud. The data has also revealed that the difference between the heat load of the inner triplets decreases with time. Also, the heat load increase at injection divides itself from heat load of the two beams. Furthermore, the heat/proton ratio does not seem to change in 2011 and 2012 (they are equivalent under similar beam conditions), suggesting that the SEY value may not have changed. It is suggested to proceed with PyECLOUD for more conclusive results. The stand-alone magnets do not show measurable heat load from the electron cloud, except for the 25ns runs...

  5. Planetary spectroscopy

    International Nuclear Information System (INIS)

    The main goal of the research is charge coupled device (CCD) spectroscopic and imaging studies of the solar system in support of spacecraft investigations. Studies include the physical behavior of comets, the atmosphere of the gaseous planets, and the solid surfaces of satellites and asteroids. The major observing program consisted of approximately 50 nights of photometry of Comet Halley in order to resolve the controversy over this comet's rotation period. This data is presently being analyzed. Additional observing projects included the spectroscopic occultation of Charon by Pluto, reflection spectroscopy of Mercury, and a spectrum of the satellite Oberon. Mercury data does not corroborate the Fe(++) absorption feature reported by McCord and Clark at 8800 A but instead potentially shows a weaker feature at longer wavelengths. This position is in much closer accord with expectations for Mercury since a band center near 8800 A implies too little Fe(++) on Mercury, especially if band shifts with temperature are considered. The Pluto project proved that the deep methane absorptions visible in their combined specta are due soley to Pluto with Charon showing a flat and featureless spectrum. It appears that if Charon ever contained a substantial methane component, the satellite's low surface gravity could not hold it and the methane evaporated and escaped

  6. MHD Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, R F; Fasoli, A; Testa, D; Sharapov, S; Berk, H L; Breizman, B; Gondhalekar, A; Mantsinen, M

    2004-03-23

    Experiments are conducted on the JET tokamak to assess the diagnostic potential of MHD active and passive spectroscopy, for the plasma bulk and its suprathermal components, using Alfv{acute e}n Eigenmodes (AEs) excited by external antennas and by energetic particles. The measurements of AE frequencies and mode numbers give information on the bulk plasma. Improved equilibrium reconstruction, in particular in terms of radial profiles of density and safety factor, is possible from the comparison between the antenna driven spectrum and that calculated theoretically. Details of the time evolution of the non-monotonic safety factor profile in advanced scenarios can be reconstructed from the frequency of ICRH-driven energetic particle modes. The plasma effective mass can be inferred from the resonant frequency of externally driven AEs in discharges with similar equilibrium profiles. The stability thresholds and the nonlinear development of the instabilities can give clues on energy and spatial distribution of the fast particle population. The presence of unstable AEs provides lower limits in the energy of ICRH generated fast ion tails. Fast ion pressure gradients and their evolution can be inferred from the stability of AEs at different plasma radial positions. Finally, the details of the AE spectrum in the nonlinear stage can be used to obtain information about the fast particle velocity space diffusion.

  7. A pyrimidine motif DNA triplex with a third N3prime;rarr;P5$prime; phosphoramidate d-C,T strand studied by FTIR and UV spectroscopy

    Science.gov (United States)

    Mondragón-Sánchez, J. A.; Liquier, J.; Gryaznov, S. M.; Taillandier, E.

    2003-12-01

    Formation of a pyrimidine motif triple stranded structure containing a N3'→P5' phosphoramidate 5'-d(TTC-TCC-TTT-CTT)-3' third strand targeting the 5'-d(AAG-AGG-AAA-GAA)-3' sequence has been followed by Fourier transform infrared (FTIR) spectroscopy and UV spectroscopy. The use of a N3'→P5' phosphoramidate d-C,T third strand is aimed at increasing triplex stability at neutral pH. FTIR spectroscopy measurements at neutral pH show a biphasic melting profile ( Tm at 25 and 54 °C). The triple helix is stabilized by the formation of T *A-T base triplets, in spite of the presence of four unprotonated cytosines in the 12mer third d-C,T phosphoramidate strand and therefore of the absence of C +*G rad C base triplets. All N3'→P5' phosphoramidate nucleoside sugars in this triple helix adopt an S-type (C2' endo) conformation. No triple helix has been detected at neutral pH when a natural isosequential phosphodiester third strand was used. By decreasing the pH, the FTIR spectra show the formation of C +*G rad C base triplets in addition to the already formed T *A rad T base triplets. The melting of this stabilized triple helix is observed at a temperature higher than that of the initial Watson-Crick duplex. The existence of N-type sugars is then detected. When the concentration is decreased, at neutral pH, UV spectroscopy measurements show that the intermolecular triple helix formed by three short 12mer strands is no longer stable. In dilute solution at acidic pH the triplex is more stable than the initial Watson-Crick duplex.

  8. Photoinduced phenoxyl radical formation from ligno- p-cresol as studied by steady-state and time-resolved EPR spectroscopy

    Science.gov (United States)

    Tero-Kubota, Shozo; Tachikawa, Takashi; Ito, Fuyuki; Matsui, Mikio; Konishi, Kazuyori

    2003-11-01

    The phenoxyl radical formation mechanism from the UV-photolysis of ligno- p-cresol in organic solvents has been investigated by steady-state and time-resolved EPR spectroscopy. It is suggested that the phenoxyl radical is generated from the o-methoxy phenol moiety in the main chain of the polymer through the dissociative photoionization by the biphotonic process from the excited triplet states.

  9. Chiroptical Spectroscopy

    Science.gov (United States)

    Gurst, Jerome E.

    1995-09-01

    A brief review of the literature, and Chemical and Engineering News in particular, reveals that the determination and use of optical activity is of increasing importance in today's commercial and research laboratories. The classical technique is to measure [alpha]D using a manual or recording polarimeter to provide a single value, the specific rotation at 589 nm. A spectropolarimeter can be used to determine optical activity through the UV-Visible spectrum (Optical Rotatory Dispersion [ORD]). At wavelengths far removed from electronic absorption bands, optical activity arises from circular birefringence, or the difference in the refractive index for left- and right-circularly polarized light; i.e., nL - nR does not equal zero for chiral materials. If the optical activity is measured through an absorption band, complex behavior is observed (a Cotton Effect curve). At an absorption band, chiral materials exhibit circular dichroism (CD), or a difference in the absorption of left- and right-circularly polarized light; epsilon L minus epsilon R does not equal zero. If the spectropolarimeter is set for the measurement of CD spectra, one observes what appears to be a UV-Vis spectrum except that some absorption bands are positive while others may be negative. Just as enantiomers have specific rotations that are equal and opposite at 589 nm (sodium D line), rotations are equal and opposite at all wavelengths, and CD measurements are equal and opposite at all wavelengths. Figure 1 shows the ORD curves for the enantiomeric carvones while Figure 2 contains the CD curves. The enantiomer of carvone that has the positive [alpha]D is obtained from caraway seeds and is known to have the S-configuration while the R-enantiomer is found in spearmint oil. Figure 1. ORD of S-(+)- and R-(-)-carvones Figure 2. CD of S-(+)- and R-(-)-carvones While little can be done to correlate stereochemistry with [alpha]D values, chiroptical spectroscopy (ORD and/or CD) often can be used to assign

  10. Singlet fission in rubrene single crystal: direct observation by femtosecond pump-probe spectroscopy.

    Science.gov (United States)

    Ma, Lin; Zhang, Keke; Kloc, Christian; Sun, Handong; Michel-Beyerle, Maria E; Gurzadyan, Gagik G

    2012-06-21

    The excited state dynamics of rubrene in solution and in the single crystal were studied by femtosecond pump-probe spectroscopy under various excitation conditions. Singlet fission was demonstrated to play a predominant role in the excited state relaxation of the rubrene crystal in contrast to rubrene in solution. Upon 500 nm excitation, triplet excitons form on the picosecond time scale via fission from the lowest excited singlet state. Upon 250 nm excitation, fission from upper excited singlet states is observed within 200 fs. PMID:22510785

  11. VizieR Online Data Catalog: NGC 5824 calcium triplet equivalent widths (Da Costa+, 2014)

    Science.gov (United States)

    da Costa, G. S.; Held, E. V.; Saviane, I.

    2016-06-01

    Observing time to follow up the possibility of an intrinsic [Fe/H] spread in NGC 5824 was allocated for intermediate-resolution spectroscopy of candidate red giant members on both the VLT with the FORS2 multi-object spectrograph, and on the Gemini-S telescope with the GMOS-S multi-object spectrograph. (1 data file).

  12. The excited triplet (T{sub 1}) state structure and vibrational properties of 2,2'-bipyridine

    Energy Technology Data Exchange (ETDEWEB)

    Lapouge, C.; Buntinx, G. [Laboratoire de Spectrochimie Infrarouge et Raman, UMR 8516 de l' Universite et du CNRS, Centre d' Etudes et de Recherches Lasers et Applications (FR 2416 du CNRS), Bat. C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq (France); Poizat, O. [Laboratoire de Spectrochimie Infrarouge et Raman, UMR 8516 de l' Universite et du CNRS, Centre d' Etudes et de Recherches Lasers et Applications (FR 2416 du CNRS), Bat. C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq (France)], E-mail: olivier.poizat@univ-lille1.fr

    2008-06-02

    The geometry of the lowest lying excited triplet state (T{sub 1}) of 2,2'-bipyridine (22BPY) was optimized by using the time-dependent density functional theory (TD-DFT) with the B3LYP functional and the SVP basis set. The T{sub 1} state is of {sup 3}B{sub u} symmetry and results from a nearly one-electron {pi}{pi}* transition from the 3b{sub g} HOMO to the 4a{sub u} LUMO. Its geometry is trans-planar and essentially characterized by a reinforcement of the interring CC bond and a quinoidal distortion of the rings. This calculated triplet structure is firmly validated by an unequivocal agreement, for four 22BPY isotopomers, between the derived theoretical vibrational frequencies and previously reported experimental time-resolved resonance Raman (TR3) spectra. Moreover, vertical transitions to the 10 lowest energy triplet states T{sub n} were calculated and the corresponding T{sub 1} state resonance Raman intensities estimated, in the short-time dynamics approximation of the Franck-Condon scattering mechanism, from the gradient of the T{sub n} potential surfaces at the T{sub 1} geometry along the totally symmetric modes. Excellent agreement with the experimental resonance Raman intensities was observed for a 4a{sub u} (LUMO) {yields} 5b{sub g} (LUMO + 3) T{sub 1} {yields} T{sub n} transition. This analysis provides a further support of the TD-DFT optimized T{sub 1} state structure of 22BPY.

  13. An apparatus for pulsed ESR and DNP experiments using optically excited triplet states down to liquid helium temperatures

    Science.gov (United States)

    Eichhorn, T. R.; Haag, M.; van den Brandt, B.; Hautle, P.; Wenckebach, W. Th.; Jannin, S.; van der Klink, J. J.; Comment, A.

    2013-09-01

    In standard Dynamic Nuclear Polarization (DNP) electron spins are polarized at low temperatures in a strong magnetic field and this polarization is transferred to the nuclear spins by means of a microwave field. To obtain high nuclear polarizations cryogenic equipment reaching temperatures of 1 K or below and superconducting magnets delivering several Tesla are required. This equipment strongly limits applications in nuclear and particle physics where beams of particles interact with the polarized nuclei, as well as in neutron scattering science. The problem can be solved using short-lived optically excited triplet states delivering the electron spin. The spin is polarized in the optical excitation process and both the cryogenic equipment and magnet can be simplified significantly. A versatile apparatus is described that allows to perform pulsed dynamic nuclear polarization experiments at X-band using short-lived optically excited triplet sates. The efficient 4He flow cryostat that cools the sample to temperatures between 4 K and 300 K has an optical access with a coupling stage for a fiber transporting the light from a dedicated laser system. It is further designed to be operated on a neutron beam. A combined pulse ESR/DNP spectrometer has been developed to observe and characterize the triplet states and to perform pulse DNP experiments. The ESR probe is based on a dielectric ring resonator of 7 mm inner diameter that can accommodate cubic samples of 5 mm length needed for neutron experiments. NMR measurements can be performed during DNP with a coil integrated in the cavity. With the presented apparatus a proton polarization of 0.5 has been achieved at 0.3 T.

  14. Highly efficient greenish-blue platinum-based phosphorescent organic light-emitting diodes on a high triplet energy platform

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y. L., E-mail: yilu.chang@mail.utoronto.ca; Gong, S., E-mail: sgong@chem.utoronto.ca; White, R.; Lu, Z. H., E-mail: zhenghong.lu@utoronto.ca [Department of Materials Science and Engineering, University of Toronto, 184 College St., Toronto, Ontario M5S 3E4 (Canada); Wang, X.; Wang, S., E-mail: wangs@chem.queensu.ca [Department of Chemistry, Queen' s University, 90 Bader Lane, Kingston, Ontario K7L 3N6 (Canada); Yang, C. [Department of Chemistry, Wuhan University, Wuhan 430072 (China)

    2014-04-28

    We have demonstrated high-efficiency greenish-blue phosphorescent organic light-emitting diodes (PHOLEDs) based on a dimesitylboryl-functionalized C^N chelate Pt(II) phosphor, Pt(m-Bptrz)(t-Bu-pytrz-Me). Using a high triplet energy platform and optimized double emissive zone device architecture results in greenish-blue PHOLEDs that exhibit an external quantum efficiency of 24.0% and a power efficiency of 55.8 lm/W. This record high performance is comparable with that of the state-of-the-art Ir-based sky-blue organic light-emitting diodes.

  15. Synthesis of skeletally diverse alkaloid-like molecules: exploitation of metathesis substrates assembled from triplets of building blocks

    Directory of Open Access Journals (Sweden)

    Sushil K. Maurya

    2013-04-01

    Full Text Available A range of metathesis substrates was assembled from triplets of unsaturated building blocks. The approach involved the iterative attachment of a propagating and a terminating building block to a fluorous-tagged initiating building block. Metathesis cascade chemistry was used to “reprogram” the molecular scaffolds. Remarkably, in one case, a cyclopropanation reaction competed with the expected metathesis cascade process. Finally, it was demonstrated that the metathesis products could be derivatised to yield the final products. At each stage, purification was facilitated by the presence of a fluorous-tagged protecting group.

  16. Electron Transfer Reaction Between Desoxyadenosine and Triplet 2-Methyl-1,4-naphthaquinone: A Laser Photolysis Study

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Introduction Electron transfer oxidation of DNA by triplet artificial photonuclease reveals a bright prospect of its application in biology and medicine. Both molecular orbital calculation and laser experiments have indicated that the homo guanine sequence should be the final localization site of photoexcited hole via long range migration within DNA[1-3]. However, the direct observation of the produced ion pairs of biomolecules especially the stabilized radical cation DNA or its components is hampered by the overwhelming transient absorption of protonated radical anion of photosensitizers, such as 2-methyl-1,4-naphthaguinonel (MQ).

  17. Temperature-Dependent Mollow Triplet Spectra from a Single Quantum Dot: Rabi Frequency Renormalization and Sideband Linewidth Insensitivity

    DEFF Research Database (Denmark)

    Wei, Yu-Jia; He, Yu; He, Yu-Ming;

    2014-01-01

    We investigate temperature-dependent resonance fluorescence spectra obtained from a single self- assembled quantum dot. A decrease of the Mollow triplet sideband splitting is observed with increasing temperature, an effect we attribute to a phonon-induced renormalization of the driven dot Rabi...... frequency. We also present first evidence for a nonperturbative regime of phonon coupling, in which the expected linear increase in sideband linewidth as a function of temperature is canceled by the corresponding reduction in Rabi frequency. These results indicate that dephasing in semiconductor quantum...

  18. $H^+ W^- Z$ contribution to the static quantities of the W boson in the context of Higgs-triplet theories

    CERN Document Server

    Tavares-Velasco, G

    2004-01-01

    We calculate the one--loop contribution from the $H^+ W^- Z$ coupling to the static electromagnetic properties of the W boson. Although this coupling is absent at the tree--level in all Higgs--doublet models, it can be induced at this order in models including Higgs--triplet representations. It is found that the $H^+ W^- Z$ contribution can be as important as those arising from other couplings including Higgs bosons, such as the standard model coupling WWH or the two--Higgs--doublet model couplings $H^+ W^- \\phi^0$ and $W W \\phi^0$, with $\\phi^0=h$, $H$ and $A$.

  19. Measurements and analysis of helium-like triplet ratios in the X-ray spectra of O-type stars

    OpenAIRE

    Leutenegger, Maurice A.; Paerels, Frits B. S.; Kahn, Steven M.; Cohen, David H.

    2006-01-01

    We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars, including accounting for the spatial distribution of the X-ray emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS data. We assume an X-ray emitting plasma spatially distributed in the wind above some minimum radius R_0. We find minimum radii of formation...

  20. Singlet oxygen triplet energy transfer-based imaging technology for mapping protein-protein proximity in intact cells.

    Science.gov (United States)

    To, Tsz-Leung; Fadul, Michael J; Shu, Xiaokun

    2014-01-01

    Many cellular processes are carried out by large protein complexes that can span several tens of nanometres. Whereas forster resonance energy transfer has a detection range of technology with a detection range of up to several tens of nanometres: singlet oxygen triplet energy transfer. We demonstrate that our method confirms the topology of a large protein complex in intact cells, which spans from the endoplasmic reticulum to the outer mitochondrial membrane and the matrix. This new method is thus suited for mapping protein proximity in large protein complexes.

  1. Identification of a (CUG)n triplet repeat RNA-binding protein and its expression in myotonic dystrophy.

    OpenAIRE

    Timchenko, L T; Miller, J. W.; Timchenko, N A; DeVore, D R; Datar, K V; Lin, L.; Roberts, R; Caskey, C T; Swanson, M.S.

    1996-01-01

    Myotonic dystrophy (DM) is an autosomal dominant neuromuscular disease that is associated with a (CTG)n repeat expansion in the 3'-untranslated region of the myotonin protein kinase (Mt-PK) gene. This study reports the isolation and characterization of a (CUG)n triplet repeat pre-mRNA/mRNA binding protein that may play an important role in DM pathogenesis. Two HeLa cell proteins, CUG-BP1 and CUG-BP2, have been purified based upon their ability to bind specifically to (CUG)8 oligonucleotides i...

  2. Reliable Prediction with Tuned Range-Separated Functionals of the Singlet-Triplet Gap in Organic Emitters for Thermally Activated Delayed Fluorescence (TADF)

    KAUST Repository

    Sun, Haitao

    2015-07-09

    The thermally activated delayed fluorescence (TADF) mechanism has recently attracted much interest in the field of organic light-emitting diodes (OLEDs). TADF relies on the presence of a very small energy gap between the lowest singlet and triplet excited states. Here, we demonstrate that time-dependent density functional theory (TD-DFT) in the Tamm-Dancoff Approximation can be very successful in the calculations of the lowest singlet and triplet excitation energies and the corresponding singlet-triplet gap when using nonempirically tuned range-separated functionals. Such functionals provide very good estimates in a series of 17 molecules used in TADF-based OLED devices, with mean absolute deviations of 0.15 eV for the vertical singlet excitation energies and 0.09 eV [0.07 eV] for the adiabatic [vertical] singlet-triplet energy gaps as well as low relative errors and high correlation coefficients compared to the corresponding experimental values. They significantly outperform conventional functionals, a feature which is rationalized on the basis of the amount of exact-exchange included and the delocalization error. The present work provides a reliable theoretical tool for the prediction and development of novel TADF-based materials with low singlet-triplet energetic splittings.

  3. A model for the [C+-GxC]n triple helix derived from observation of the C+-GxC base triplet in a crystal structure.

    Science.gov (United States)

    Nunn, C M; Trent, J O; Neidle, S

    1997-10-13

    A molecular modelling study on the [C+-GxC]n triple helix is reported. We have observed the C+-GxC base triplet in the crystal structure of an oligonucleotide-drug complex, between the minor-groove drug netropsin and the decanucleotide d(CGCAATTGCG)2. The complex was crystallised at pH 7.0, but the crystal structure, at a resolution of 2.4 A, shows that a terminal cytosine has become protonated and participates in a parallel C+-GxC base triplet. The structure of this triplet and its associated sugar-phosphate backbones have been energy-refined and then used to generate a triple helix. This has characteristics of the B-type family of DNA structures for two strands, with the third, the C+ strand, having backbone conformations closer to the A family. PMID:9369239

  4. Accurate adiabatic singlet-triplet gaps in atoms and molecules employing the third-order spin-flip algebraic diagrammatic construction scheme for the polarization propagator.

    Science.gov (United States)

    Lefrancois, Daniel; Rehn, Dirk R; Dreuw, Andreas

    2016-08-28

    For the calculation of adiabatic singlet-triplet gaps (STG) in diradicaloid systems the spin-flip (SF) variant of the algebraic diagrammatic construction (ADC) scheme for the polarization propagator in third order perturbation theory (SF-ADC(3)) has been applied. Due to the methodology of the SF approach the singlet and triplet states are treated on an equal footing since they are part of the same determinant subspace. This leads to a systematically more accurate description of, e.g., diradicaloid systems than with the corresponding non-SF single-reference methods. Furthermore, using analytical excited state gradients at ADC(3) level, geometry optimizations of the singlet and triplet states were performed leading to a fully consistent description of the systems, leading to only small errors in the calculated STGs ranging between 0.6 and 2.4 kcal/mol with respect to experimental references. PMID:27586899

  5. The improved efficiency of low molecular weight organic solar cells doped with a Cu(I) triplet material

    Science.gov (United States)

    Su, Bin; Gao, Lin; Li, Xiuying; Che, Guangbo; Zhu, Enwei; Wang, Bo; Yan, Yongsheng

    2016-08-01

    We developed a method to improve the performance of the copper phthalocyanine (CuPc)/fullerene (C60) organic solar cells (OSCs) by doping CuPc with a long triplet lifetime material. By doping [Cu(bis[2-(diphenylphosphino)phenyl]ether)(benzo[i]dipyrido[3,2-a:2',3'-c]phenazine)]BF4 (CuDB) into CuPc, the enhanced short-circuit current density ( J SC) of 6.213 mA/cm2, open-circuit voltage ( V OC) of 0.39 V and a peak power conversion efficiency (PCE) of 0.92% compared to 0.79% of the standard CuPc/C60 OSCs are achieved under 1 sun AM 1.5 G illumination at an intensity of 100 mW/cm2. The performance improvement is mainly attributed to the long triplet lifetime of CuDB (τ = 70.05 μs) which leads to more effective exciton dissociation.

  6. Observations and Bayesian location methodology of transient acoustic signals (likely blue whales) in the Indian Ocean, using a hydrophone triplet.

    Science.gov (United States)

    Le Bras, Ronan J; Kuzma, Heidi; Sucic, Victor; Bokelmann, Götz

    2016-05-01

    A notable sequence of calls was encountered, spanning several days in January 2003, in the central part of the Indian Ocean on a hydrophone triplet recording acoustic data at a 250 Hz sampling rate. This paper presents signal processing methods applied to the waveform data to detect, group, extract amplitude and bearing estimates for the recorded signals. An approximate location for the source of the sequence of calls is inferred from extracting the features from the waveform. As the source approaches the hydrophone triplet, the source level (SL) of the calls is estimated at 187 ± 6 dB re: 1 μPa-1 m in the 15-60 Hz frequency range. The calls are attributed to a subgroup of blue whales, Balaenoptera musculus, with a characteristic acoustic signature. A Bayesian location method using probabilistic models for bearing and amplitude is demonstrated on the calls sequence. The method is applied to the case of detection at a single triad of hydrophones and results in a probability distribution map for the origin of the calls. It can be extended to detections at multiple triads and because of the Bayesian formulation, additional modeling complexity can be built-in as needed. PMID:27250159

  7. Pair and triplet approximation of a spatial lattice population model with multiscale dispersal using Markov chains for estimating spatial autocorrelation.

    Science.gov (United States)

    Hiebeler, David E; Millett, Nicholas E

    2011-06-21

    We investigate a spatial lattice model of a population employing dispersal to nearest and second-nearest neighbors, as well as long-distance dispersal across the landscape. The model is studied via stochastic spatial simulations, ordinary pair approximation, and triplet approximation. The latter method, which uses the probabilities of state configurations of contiguous blocks of three sites as its state variables, is demonstrated to be greatly superior to pair approximations for estimating spatial correlation information at various scales. Correlations between pairs of sites separated by arbitrary distances are estimated by constructing spatial Markov processes using the information from both approximations. These correlations demonstrate why pair approximation misses basic qualitative features of the model, such as decreasing population density as a large proportion of offspring are dropped on second-nearest neighbors, and why triplet approximation is able to include them. Analytical and numerical results show that, excluding long-distance dispersal, the initial growth rate of an invading population is maximized and the equilibrium population density is also roughly maximized when the population spreads its offspring evenly over nearest and second-nearest neighboring sites.

  8. Singlet-Triplet Transition in Quantum Dots Confined by Triangular and Bowl-Like Potentials: the Effect of Electric Fields

    Institute of Scientific and Technical Information of China (English)

    SUN Lian-Liang; LI Shu-Shen

    2005-01-01

    @@ We theoretically investigate the energy spectra of two-electron two-dimensional (2e 2D) quantum dots (QDs)confined by triangular potentials and bowl-like potentials in a magnetic field by exact diagonalization in the framework of effective mass theory. An in-plane electric field is found to contribute to the singlet-triplet transition of the ground state of the 2e 2D QDs confined by triangular or bowl-like potentials in a perpendicular magnetic field. The stronger the in-plane electric field, the smaller the magnetic field for the total spin of the ground states in the dot systems to change from S = 0 to S = 1. However, the influence of anin-plane electric field on the singlettriplet transition of the ground state of two electrons in a triangular QD modulated by a perpendicular magnetic field is quite small because the triangular potential just deviates from the harmonic potential well slightly. We find that the strength of the perpendicular magnetic field needed for the spin singlet-triplet transition of the ground state of the QD confined by a bowl-like potential is reduced drastically by applying an in-plane electric field.

  9. Can the 750-GeV diphoton resonance be the singlet Higgs boson of custodial Higgs triplet model?

    Science.gov (United States)

    Chiang, Cheng-Wei; Kuo, An-Li

    2016-09-01

    The observation of diphoton excess around the mass of 750 GeV in LHC Run-II motivates us to consider whether the singlet Higgs boson in the custodial Higgs triplet model can serve as a good candidate because an earlier study of comprehensive parameter scan shows that it can have the right mass in the viable mass spectra. By assuming the singlet Higgs mass at 750 GeV, its total width less than 50 GeV and imposing constraints from the LHC 8-TeV data, we identify an approximately linear region on the (vΔ , α) plane along which the exotic Higgs boson masses satisfy a specific hierarchy and have lower possible spectra, where vΔ denotes the triplet vacuum expectation value and α is the mixing angle between the singlet Higgs boson and the standard model-like Higgs boson. Although the diphoton decay rate can be enhanced by charged Higgs bosons running in the loop in this region, it is mostly orders of magnitude smaller than that required for the observed production rate, except for the small vΔ region when the diphoton fusion production mechanism becomes dominant. Nonetheless, this part of parameter space suffers from the problems of breakdown of perturbativity and large uncertainties in the photon parton distribution function of proton.

  10. Observations and Bayesian location methodology of transient acoustic signals (likely blue whales) in the Indian Ocean, using a hydrophone triplet.

    Science.gov (United States)

    Le Bras, Ronan J; Kuzma, Heidi; Sucic, Victor; Bokelmann, Götz

    2016-05-01

    A notable sequence of calls was encountered, spanning several days in January 2003, in the central part of the Indian Ocean on a hydrophone triplet recording acoustic data at a 250 Hz sampling rate. This paper presents signal processing methods applied to the waveform data to detect, group, extract amplitude and bearing estimates for the recorded signals. An approximate location for the source of the sequence of calls is inferred from extracting the features from the waveform. As the source approaches the hydrophone triplet, the source level (SL) of the calls is estimated at 187 ± 6 dB re: 1 μPa-1 m in the 15-60 Hz frequency range. The calls are attributed to a subgroup of blue whales, Balaenoptera musculus, with a characteristic acoustic signature. A Bayesian location method using probabilistic models for bearing and amplitude is demonstrated on the calls sequence. The method is applied to the case of detection at a single triad of hydrophones and results in a probability distribution map for the origin of the calls. It can be extended to detections at multiple triads and because of the Bayesian formulation, additional modeling complexity can be built-in as needed.

  11. The photospheric solar oxygen project: IV. 3D-NLTE investigation of the 777 nm triplet lines

    CERN Document Server

    Steffen, M; Caffau, E; Ludwig, H -G; Bonifacio, P; Cayrel, R; Kučinskas, A; Livingston, W C

    2015-01-01

    The solar photospheric oxygen abundance is still widely debated. Adopting the solar chemical composition based on the "low" oxygen abundance, as determined with the use of three-dimensional (3D) hydrodynamical model atmospheres, results in a well-known mismatch between theoretical solar models and helioseismic measurements that is so far unresolved. We carry out an independent redetermination of the solar oxygen abundance by investigating the center-to-limb variation of the OI IR triplet lines at 777 nm in different sets of spectra with the help of detailed synthetic line profiles based on 3D hydrodynamical CO5BOLD model atmospheres and 3D non-LTE line formation calculations with NLTETD. The idea is to simultaneously derive the oxygen abundance,A(O), and the scaling factor SH that describes the cross-sections for inelastic collisions with neutral hydrogen relative the classical Drawin formula. The best fit of the center-to-limb variation of the triplet lines achieved with the CO5BOLD 3D solar model is clearly...

  12. Saturation effects in fluorescence correlation spectroscopy

    Science.gov (United States)

    Davis, Lloyd M.; Shen, Guoqing; Ball, David A.

    2005-03-01

    Fluorescence correlation spectroscopy (FCS) could provide a more useful tool for intracellular studies and biological sample characterization if measurement times could be reduced. While an increase in laser power can enable an autocorrelation function (ACF) with adequate signal-to-noise to be acquired within a shorter measurement time, excitation saturation then leads to distortion of the ACF and systematic errors in the measurement results. An empirical method for achieving reduced systematic errors by employing a fitting function with an additional adjustable parameter has been previously introduced for two-photon FCS. Here we provide a unified physical explanation of excitation saturation effects for the three cases of continuous-wave, pulsed one-photon excitation, and two-photon excitation FCS. When the time between laser pulses is longer than the fluorescence lifetime, the signal rate at which excitation saturation occurs is lower for pulsed excitation than for cw excitation, and due to the disparate timescales of the photophysical processes following excitation, it is lower still for two-photon excitation. We use a single-molecule description of FCS to obtain improved analytical ACF fitting functions for the three cases. The fitting functions more accurately account for saturation effects than those previously employed without the need for an additional empirical parameter. Use of these fitting functions removes systematic errors and enables measurements to be acquired more quickly by use of higher laser powers. Increase of background, triplet photophysics, and the cases of scanning FCS and fluorescence cross-correlation spectroscopy are also discussed. Experimental results acquired with a custom built apparatus are presented.

  13. Automatic stellar spectra parameterisation in the IR Ca ii triplet region

    Science.gov (United States)

    Kordopatis, G.; Recio-Blanco, A.; de Laverny, P.; Bijaoui, A.; Hill, V.; Gilmore, G.; Wyse, R. F. G.; Ordenovic, C.

    2011-11-01

    Context. Galactic archaeology aims to determine the evolution of the Galaxy from the chemical and kinematical properties of its individual stars. This requires the analysis of data from large spectroscopic surveys, with sample sizes in tens of thousands at present, with millions of stars being reached in the near future. Such large samples require automated analysis techniques and classification algorithms to obtain robust estimates of the stellar parameter values. Several on-going and planned spectroscopic surveys have selected their wavelength region to contain the IR Ca ii triplet (~λλ 8500 Å) and the work presented in this paper focuses on the automatic analysis of such spectra. Aims: We aim to develop and test an automatic method by which one can obtain estimates of values of the stellar atmospheric parameters (effective temperature, surface gravity, overall metallicity) from a stellar spectrum. We also explore the degeneracies in parameter space, estimate the uncertainties in the derived parameter values and investigate the consequences of these limitations for achieving the goals of galactic archaeology. Methods: We investigated two algorithms, both of which compare the observed spectrum to a grid of synthetic spectra, but each uses a different mathematical approach for finding the optimum match and hence the best values of the stellar parameters. Our investigation of these algorithms' robustness can be widely applied because it amplifies the main problems that the other methods can encounter. The first algorithm, MATISSE, derives the values of each stellar parameter through a local fit to the spectrum such that each pixel in wavelength space is treated separately. The sensitivity of the flux at each wavelength to the value of a given stellar parameter is determined from the synthetic spectra. The observed spectrum is then projected using these sensitivity vectors to give an estimated value of the stellar parameters. This value depends on finding the true

  14. A kinetically blocked 1,14:11,12-dibenzopentacene: A persistent triplet diradical of a non-Kekulé polycyclic benzenoid hydrocarbon

    KAUST Repository

    Li, Yuan

    2014-01-01

    The synthesis of high-spin polycyclic hydrocarbons is very challenging due to their extremely high reactivity. Herein, we report the synthesis and characterization of a kinetically blocked 1,14:11,12-dibenzopentacene, DP-Mes, which represents a rare persistent triplet diradical of a non-Kekulé polycyclic benzenoid hydrocarbon. In contrast to its structural isomer 1,14:7,8-dibenzopentacene (heptazethrene) with a singlet biradical ground state, DP-Mes is a triplet diradical as confirmed by ESR and ESTN measurements and density functional theory calculations. DP-Mes also displays intermolecular antiferromagnetic spin interactions in solution at low temperature. © 2014 the Partner Organisations.

  15. Basic molecular spectroscopy

    CERN Document Server

    Gorry, PA

    1985-01-01

    BASIC Molecular Spectroscopy discusses the utilization of the Beginner's All-purpose Symbolic Instruction Code (BASIC) programming language in molecular spectroscopy. The book is comprised of five chapters that provide an introduction to molecular spectroscopy through programs written in BASIC. The coverage of the text includes rotational spectra, vibrational spectra, and Raman and electronic spectra. The book will be of great use to students who are currently taking a course in molecular spectroscopy.

  16. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1997-01-01

    This series describes selected advances in the area of atomic spectroscopy. It is primarily intended for the reader who has a background in atmoic spectroscopy; suitable to the novice and expert. Although a widely used and accepted method for metal and non-metal analysis in a variety of complex samples, Advances in Atomic Spectroscopy covers a wide range of materials. Each Chapter will completely cover an area of atomic spectroscopy where rapid development has occurred.

  17. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1995-01-01

    This series describes selected advances in the area of atomic spectroscopy. It is promarily intended for the reader who has a background in atmoic spectroscopy; suitable to the novice and expert. Although a widely used and accepted method for metal and non-metal analysis in a variety of complex samples, Advances in Atomic Spectroscopy covers a wide range of materials. Each Chapter will completely cover an area of atomic spectroscopy where rapid development has occurred.

  18. Symposium on atomic spectroscopy

    International Nuclear Information System (INIS)

    Topics covered by the conference include: fast beam spectroscopy; astrophysical and other spectra; highly ionized spectroscopy; complex spectra; rydberg levels; fine structure, hyperfine structure and isotope shift; lineshapes; lifetimes, oscillator strengths and Einstein coefficients; and spectroscopy with lasers. Abstracts of the conference papers are presented

  19. Symposium on atomic spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Topics covered by the conference include: fast beam spectroscopy; astrophysical and other spectra; highly ionized spectroscopy; complex spectra; rydberg levels; fine structure, hyperfine structure and isotope shift; lineshapes; lifetimes, oscillator strengths and Einstein coefficients; and spectroscopy with lasers. Abstracts of the conference papers are presented. (GHT)

  20. Coherent Raman spectroscopy

    CERN Document Server

    Eesley, G L

    1981-01-01

    Coherent Raman Spectroscopy provides a unified and general account of the fundamental aspects of nonlinear Raman spectroscopy, also known as coherent Raman spectroscopy. The theoretical basis from which coherent Raman spectroscopy developed is described, along with its applications, utility, and implementation as well as advantages and disadvantages. Experimental data which typifies each technique is presented. This book is comprised of four chapters and opens with an overview of nonlinear optics and coherent Raman spectroscopy, followed by a discussion on nonlinear transfer function of matter

  1. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    2000-01-01

    This fifth volume of the successful series Advances in Atomic Spectroscopy continues to discuss and investigate the area of atomic spectroscopy.It begins with a description of the use of various atomic spectroscopic methods and applications of speciation studies in atomic spectroscopy. The emphasis is on combining atomic spectroscopy with gas and liquid chromatography. In chapter two the authors describe new developments in tunable lasers and the impact they will have on atomic spectroscopy. The traditional methods of detection, such as photography and the photomultiplier, and how they are being replaced by new detectors is discussed in chapter three. The very active area of glow discharge atomic spectrometry is presented in chapter four where, after a brief introduction and historical review, the use of glow discharge lamps for atomic spectroscopy and mass spectrometry are discussed. Included in this discussion is geometry and radiofrequency power. The future of this source in atomic spectroscopy is also dis...

  2. Experimental investigations of He II heat transfer through a short section of LHC inner triplet quadrupole heat exchanger

    CERN Document Server

    Darve, C; Nicol, T H; Peterson, Thomas J

    2001-01-01

    The LHC inner triplet quadrupoles, cooled by pressurized He II, are subjected to a total heat load of more than 7 W/m at nominal luminosity. The heat absorbed in pressurized He II will be transferred to the saturated, two-phase He II via a corrugated copper pipe. Experimental investigations of He II heat transfer across the corrugated pipe are reported. The test sample of corrugated pipe is filled with pressurized He II and with saturated He II on the outside. The maximum heat flux to the test sample is up to 145 W/m /sup 2/. The characteristics of the corrugated copper pipes under investigation are the Kapitza resistance, thermal conductivity of the material and the geometry of the pipe. The test results for a series of bath temperatures and surface treatments are included. (5 refs).

  3. Measurements and analysis of helium-like triplet ratios in the X-ray spectra of O-type stars

    CERN Document Server

    Leutenegger, M A; Kahn, S M; Cohen, D H; Leutenegger, Maurice A.; Paerels, Frits B. S.; Kahn, Steven M.; Cohen, David H.

    2006-01-01

    We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars, including accounting for the spatial distribution of the X-ray emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS data. We assume an X-ray emitting plasma spatially distributed in the wind above some minimum radius R_0. We find minimum radii of formation typically in the range of 1.25 < R_0 / R_* < 1.67, which is consistent with results obtained independently from line profile fits. We find no evidence for anomalously low f/i ratios and we do not require the existence of X-ray emitting plasmas at radii that are too small to generate sufficiently strong shocks.

  4. First-principles calculation of the electronic structure of condensed spin-polarized excited triplet-state helium

    Energy Technology Data Exchange (ETDEWEB)

    LaViolette, R.A.; Godin, T.J.; Switendick, A.C. [Idaho National Engineering Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415-2208 (United States)

    1995-08-15

    The excited triplet-state (1{ital s}2{ital s},{sup 3}{ital S}) helium atom (He{sup *}) is long-lived (2.5 h) in isolation. We have investigated the properties of a hypothetical condensed phase of spin-polarized He{sup *} on the bcc and fcc lattices using density-functional theory and the full-potential linear-augmented-plane-wave method. We found that each lattice provides over 1 eV of binding as a metallic {ital s}-{ital p} ferromagnet with a 1-eV indirect gap, and a 4-eV direct gap, between the occupied spin-up and the unoccupied spin-down bands. The surprising existence of such a gap suggests that condensed He{sup *} might also be metastable.

  5. Measurements and Analysis of Helium-Like Triplet Ratios in the X-Ray Spectra of O-Type Stars

    Energy Technology Data Exchange (ETDEWEB)

    Leutenegger, Maurice A.; Paerels, Frits B.S.; /Columbia U., Astron. Astrophys.; Kahn, Steven M.; /SLAC; Cohen, David H.; /Swarthmore Coll.

    2006-06-19

    We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars, including accounting for the spatial distribution of the X-ray emitting plasma and using the detailed photospheric UV spectrum. Measurements are made for four O stars using archival Chandra HETGS data. We assume an X-ray emitting plasma spatially distributed in the wind above some minimum radius R{sub 0}. We find minimum radii of formation typically in the range of 1.25 < R{sub 0}/R{sub *} < 1.67, which is consistent with results obtained independently from line profile fits. We find no evidence for anomalously low f/i ratios and we do not require the existence of X-ray emitting plasmas at radii that are too small to generate sufficiently strong shocks.

  6. Spin-triplet paired state induced by Hund's rule coupling and correlations: a fully statistically consistent Gutzwiller approach.

    Science.gov (United States)

    Spałek, J; Zegrodnik, M

    2013-10-30

    The intrasite and intersite spin-triplet pairing gaps induced by interband Hund's rule coupling and their correlations are analyzed in the doubly degenerate Hubbard Hamiltonian. To include the effect of correlations, the statistically consistent Gutzwiller approximation is used. In this approach the consistency means that the averages calculated from the self-consistent equations and those determined variationally coincide with each other. Emphasis is put on the solution for which the average particle number is conserved when carrying out the Gutzwiller projection. This method leads to a stable equal-spin paired state in the so-called repulsive interactions limit (U > 3J) in the regime of moderate correlations. The interband hybridization introduces an inequivalence of the bands which, above a critical magnitude, suppresses the paired state due to both the Fermi-wavevector mismatch for the Cooper pair and the interband hopping allowed by the Pauli principle.

  7. Photodegradation mechanism of sulfonamides with excited triplet state dissolved organic matter: A case of sulfadiazine with 4-carboxybenzophenone as a proxy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yingjie; Wei, Xiaoxuan; Chen, Jingwen, E-mail: jwchen@dlut.edu.cn; Xie, Hongbin; Zhang, Ya-nan

    2015-06-15

    Highlights: • Excited triplet state of dissolved organic matter ({sup 3}DOM{sup *}) is largely responsible for the enhanced photodegradation of sulfadiazine. • Electron followed by proton transfer is a major mechanism for the reactions of sulfadiazine with {sup 3}DOM{sup *} proxies. • Two reaction sites (amino- or sulfonyl-N) and sulfadiazine radicals were identified in the reactions of sulfadiazine with {sup 3}DOM{sup *} proxies. - Abstract: Excited triplet states of dissolved organic matter ({sup 3}DOM*) are important players for photodegradation sulfonamide antibiotics (SAs) in sunlit natural waters. However, the triplet-mediated reaction mechanism was poorly understood. In this study, we investigated the reaction adopting sulfadiazine as a representative SA and 4-carboxybenzophenone (CBBP)as a proxy of DOM. Results showed that the excited triplet state of CBBP ({sup 3}CBBP*) is responsible for the photodegradation of sulfadiazine. The reaction of {sup 3}CBBP* with substructure model compounds verified there are two reaction sites (amino-or sulfonyl-N atoms) of sulfadiazine. Density functional theory calculations were performed, which unveiled that electrons transfer from the N reaction sites to the carbonyl oxygen atom of {sup 3}CBBP* moiety, followed by proton transfers, leading to the formation of sulfadiazine radicals. Laser flash photolysis experiments were performed to confirm the mechanism. Thus, this study identified that the photodegradation mechanism of SAs initiated by {sup 3}DOM*, which is important for understanding the photochemical fate, predicting the photoproducts, and assessing the ecological risks of SAs in the aquatic environment.

  8. High orbital angular momentum states in H sub 2 and D sub 2. III. Singlet--triplet splittings, energy levels, and ionization potentials

    Energy Technology Data Exchange (ETDEWEB)

    Jungen, C. (Laboratoire de Photophysique Moleculaire du CNRS, Universite de Paris-Sud, 91405 Orsay (France)); Dabrowski, I.; Herzberg, G.; Vervloet, M. (National Research Council of Canada, 100 Sussex Drive, Ottawa K1A 0R6 (Canada))

    1990-08-15

    The 5{ital g}--4 {ital f} Rydberg groups of H{sub 2} and D{sub 2} first studied in paper I have been obtained with a tenfold increase in resolution which made it possible to resolve the singlet from the triplet components. As a result we can now establish separately precise values for the energy levels in the triplet and singlet systems. For this purpose we have remeasured a number of transitions between the lower energy levels for which at present only old measurements are available. In particular we obtain accurate values for the energies of the lowest (stable) triplet state {ital a}{sup 3}{Sigma}{sup +}{sub {ital g}} relative to the singlet ground state, as well as of the ionization potential. The values obtained for the former are more accurate than obtained from singlet--triplet anticrossings while the latter are of similar accuracy as those reported recently by McCormack {ital et} {ital al}. (Phys. Rev. A {bold 39}, 2260 (1989)) and fit well within this accuracy with the most recent {ital ab} {ital initio} values.

  9. Efficient triplet application in exciplex delayed-fluorescence OLEDs using a reverse intersystem crossing mechanism based on a ΔES-T of around zero.

    Science.gov (United States)

    Zhang, Tianyou; Chu, Bei; Li, Wenlian; Su, Zisheng; Peng, Qi Ming; Zhao, Bo; Luo, Yongshi; Jin, Fangming; Yan, Xingwu; Gao, Yuan; Wu, Hairuo; Zhang, Feng; Fan, Di; Wang, Junbo

    2014-08-13

    We demonstrate highly efficient exciplex delayed-fluorescence organic light-emitting diodes (OLEDs) in which 4,4',4″-tris[3-methylphenyl(phenyl)aminotriphenylamine (m-MTDATA) and 4,7-diphenyl-1,10-phenanthroline (Bphen) were selected as donor and acceptor components, respectively. Our m-MTDATA:Bphen exciplex electroluminescence (EL) mechanism is based on reverse intersystem crossing (RISC) from the triplet to singlet excited states. As a result, an external quantum efficiency (EQE) of 7.79% at 10 mA/cm(2) was observed, which increases by 3.2 and 1.5 times over that reported in Nat. Photonics 2012, 6, 253 and Appl. Phys. Lett. 2012, 101, 023306, respectively. The high EQE would be attributed to a very easy RISC process because the energy difference between the singlet and triplet excited states is almost around zero. The verdict was proven by photoluminescence (PL) rate analysis at different temperatures and time-resolved spectral analysis. Besides, the study of the transient PL process indicates that the presence of an unbalanced charge in exciplex EL devices is responsible for the low EQE and high-efficiency roll-off. When the exciplex devices were placed in a 100 mT magnetic field, the permanently positive magnetoelectroluminescence and magnetoconductivity were observed. The magnetic properties confirm that the efficient exciplex EL only originates from delayed fluorescence via RISC processes but is not related to the triplet-triplet annihilation process. PMID:24840782

  10. Resonance-enhanced multiphoton ionization photoelectron spectroscopy of even-parity autoionizing Rydberg states of atomic sulphur

    OpenAIRE

    Woutersen, S.; Milan,, M; Lange; Buma, W.J.

    1997-01-01

    Several previously unobserved Rydberg states of the sulphur atom above the lowest ionization threshold are identified and assigned using (2 + 1) resonance-enhanced multiphoton-ionization photoelectron spectroscopy. All states were accessed by two-photon transitions from either the 3P ground or the 1D excited state, prepared by in situ photodissociation of H2S. The observed states derive from the (2Do)5p and (2Po)4p configurations. For the (2Do)5p 3F and (2Po)4p 3D triplets, extensive photoele...

  11. Phenylcarbazole and phosphine oxide/sulfide hybrids as host materials for blue phosphors: effectively tuning the charge injection property without influencing the triplet energy.

    Science.gov (United States)

    Wu, Jie; Liao, Yi; Wu, Shui-Xing; Li, Hai-Bin; Su, Zhong-Min

    2012-02-01

    Compared with red and green phosphorescent organic light-emitting diodes (PHOLEDs), efficient blue PHOLEDs are still scarce, because it is difficult for the host materials for blue phosphors to achieve a trade-off between a wide triplet energy and good charge injection properties. We theoretically studied a series of hybrid phosphine oxide/sulfide-phenylcarbazole host molecules (PO(S)PhCBZs) for blue phosphors through different linkage modes between phenylcarbazole (PhCBZ) and phosphine oxide/sulfide (PO/PS) moieties. The results indicate that the singlet excitons of all PO(S)-PhCBZs are delocalized over the entire molecule with intramolecular charge transfer (ICT) character and different linkage modes cause various degrees of ICT, which determines the injection abilities of carriers from neighboring layers following the order: PO-Phs (PO linked to the phenyl of PhCBZ) > para-POs (PO linked to the para-positions of PhCBZ) > meta-POs (PO linked to the meta-positions of PhCBZ). By contrast, the triplet excitons are confined to the carbazole unit for all PO(S)-PhCBZs. High triplet energies (E(T)) are therefore kept up for all systems, except for para-POs showing a slight drop in E(T) due to the delocalization of their triplet excitons to the phenyl moiety of PhCBZ. All hybrid PO(S)-PhCBZs, especially PO(s)-Phs, exhibit an enhancement in electron injection and triplet energy compared with the most widely used host material (N,N-dicarbazolyl-3,5-benzene) for blue PHOLEDs, and thereby have great potential for application in highly efficient light emitting diodes. PMID:22193557

  12. 巴戟天含药血清对原代破骨细胞RANK和CA II mRNA表达的影响%Effect of morinda officinalis-containing serum on the mRNA expression of RANK and CAII in primary osteoclasts in ovariectomized rats

    Institute of Scientific and Technical Information of China (English)

    何剑全; 陈健; 郑素玉; 张永晟

    2013-01-01

    目的 观察巴戟天含药血清对原代破骨细胞RANK和CA II mRNA表达的影响.方法 取SPF级大鼠48只,随机分成正常组12只和去势组36只,正常组切去卵巢周围部分脂肪,去势组切除卵巢.3个月后测定两组雌激素水平并将去势组随机分为骨质疏松组,骨质疏松+雌激素组,骨质疏松+巴戟天含药血清组.采用机械分离法提取各组的破骨细胞,培养5 d后,TRAP染色及电镜扫描骨片等的方法鉴定破骨细胞.最后用雌激素或巴戟天含药血清干预3 d,以RT-PCR法检测各组RANK和CAIImRNA表达.采用单因素方差分析或多样本均数两两比较进行统计分析.结果 去势组后大鼠雌激素水平低于正常组(P<0.01).骨质疏松组破骨细胞RANK和CAII表达均高于正常组(P<0.05,P<0.05);巴戟天含药血清可降低骨质疏松后大鼠破骨细胞RANK和CA II的表达(P<0.05,P<0.05).结论 巴戟天和雌激素均可降低骨质疏松大鼠破骨细胞RANK和CAII的表达,从而达到抑制骨质疏松的作用.%Objective To observe the effect of morinda officinalis-containing serum on the mRNA expression of RANK and CAII in primary osteoclasts in ovariectomized rats. Methods Forty-eight female SPF rats were randomly divided into 2 groups: SHAM group (n=12) and OVX group (n=36). Rats in SHAM group and ovariectomy group were treated with PBS, while rats in organic gallium group were treated with organic gallium. After the treatment for 8 weeks, the fifth lumbar vertebrae and the femur of rats were collected. The bone trabecular structure was detected using micro-CT. The percentage of bone trabecular in total bone mass (BV/TV) was detected using histomorphology method. Mechanical strength of the femoral neck was tested using biomechanical test. Biochemical markers including serum TRAP, ALP, calcium, and phosphorus were detected. Results Micro-CT tests showed that the mean trabecular thickness (Tb.Th) and the cortical thickness (Ct. Th) in organic

  13. Ultrahigh spatiotemporal resolved spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LI; Zhi

    2007-01-01

    We review the technique and research of the ultrahigh spatiotemporal resolved spectroscopy and its applications in the field of the ultrafast dynamics of mesoscopic systems and nanomaterials. Combining femtosecond time-resolved spectroscopy and scanning near-field optical microscopy (SNOM), we can obtain the spectra with ultrahigh temporal and spatial resolutions simultaneously. Some problems in doing so are discussed. Then we show the important applications of the ultrahigh spatiotemporal resolved spectroscopy with a few typical examples.……

  14. Spectroscopy for Dummies

    DEFF Research Database (Denmark)

    Lindvold, Lars René

    This presentation will give short introduction to the most pertinent topics of optical spectroscopy. The following topics will be discussed: • The origin of spectra in UV, VIS and IR spectral range • Spectroscopic methods like absorption, luminescence and Raman • Wavelength dispersive optical...... components • Materials for use optical spectroscopy • Spectrometer geometries • Detectors for use in spectrometer • Practical examples of optical spectroscopy The objective of this presentation is to give the audience a good feel for the range of possibilities that optical spectroscopy can provide....

  15. Metallomic EPR spectroscopy.

    Science.gov (United States)

    Hagen, Wilfred R

    2009-09-01

    Based on explicit definitions of biomolecular EPR spectroscopy and of the metallome, this tutorial review positions EPR in the field of metallomics as a unique method to study native, integrated systems of metallobiomolecular coordination complexes subject to external stimuli. The specific techniques of whole-system bioEPR spectroscopy are described and their historic, recent, and anticipated applications are discussed.

  16. Heterodyned holographic spectroscopy

    NARCIS (Netherlands)

    Douglas, NG

    1997-01-01

    In holographic spectroscopy an image of an interference pattern is projected onto a detector and transformed back to the input spectrum. The general characteristics are similar to those of Fourier transform spectroscopy, but the spectrum is obtained without scanning. In the heterodyned arrangement o

  17. Coherent detection spectroscopy

    NARCIS (Netherlands)

    Bueren, H.G. van

    1969-01-01

    Various methods of optical spectroscopy are compared, with special emphasis on resolution and acceptance of the systems. It is shown that coherent detection with a laser as a local oscillator has important advantages for specific applications in astronomical spectroscopy and interferometry, especial

  18. New insights into DNA triplexes: residual twist and radial difference as measures of base triplet non-isomorphism and their implication to sequence-dependent non-uniform DNA triplex

    OpenAIRE

    Thenmalarchelvi, R.; Yathindra, N

    2005-01-01

    DNA triplexes are formed by both isomorphic (structurally alike) and non-isomorphic (structurally dissimilar) base triplets. It is espoused here that (i) the base triplet non-isomorphism may be articulated in structural terms by a residual twist (Δt°), the angle formed by line joining the C1′…C1′ atoms of the adjacent Hoogsteen or reverse Hoogsteen (RH) base pairs and the difference in base triplet radius (Δr Å), and (ii) their influence on DNA triplex is largely mechanistic, leading to the p...

  19. Generating Light from Upper Excited Triplet States: A Contribution to the Indirect Singlet Yield of a Polymer OLED, Helping to Exceed the 25% Singlet Exciton Limit

    Science.gov (United States)

    Jankus, Vygintas; Aydemir, Murat; Dias, Fernando B.

    2016-01-01

    The mechanisms by which light is generated in an organic light emitting diode have slowly been elucidated over the last ten years. The role of triplet annihilation has demonstrated how the “spin statistical limit” can be surpassed, but it cannot account for all light produced in the most efficient devices. Here, a further mechanism is demonstrated by which upper excited triplet states can also contribute to indirect singlet production and delayed fluorescence. Since in a device the population of these TN states is large, this indirect radiative decay channel can contribute a sizeable fraction of the total emission measured from a device. The role of intra‐ and interchain charge transfer states is critical in underpinning this mechanism.

  20. Quantum yield of triplet formation of riboflavin in aqueous solution and of flavin mononucleotide bound to the LOV1 domain of Phot1 from Chlamydomonas reinhardtii

    International Nuclear Information System (INIS)

    The quantum yields of triplet formation, phiT, of riboflavin, and of flavin mononucleotide (FMN) bound to wild-type LOV1 domain (LOV1-WT) or bound to a mutated LOV1 domain (LOV1-C57S, cysteine 57 replaced by serine) of the photo-receptor Phot1 from the green alga Chlamydomonas reinhardtii are determined by picosecond laser double-pulse excitation and time-resolved fluorescence detection. The determined quantum yields of triplet formation are phiT=0.375±0.05 for riboflavinin in aqueous solution at pH=7, phiT=0.225±0.04 for FMN in LOV1-C57S in aqueous solution at pH=8, and phiT=0.255±0.04 for FMN in LOV1-WT in aqueous solution at pH = 8